diff --git a/src/backend/graph.cpp b/src/backend/graph.cpp
index 04a55881..c1f12b93 100644
--- a/src/backend/graph.cpp
+++ b/src/backend/graph.cpp
@@ -93,7 +93,8 @@ namespace boss {
         boost::tie(vit, vit_end) = boost::vertices(graph);
 
         for (vit, vit_end; vit != vit_end; ++vit) {
-            if (boost::iequals(graph[*vit]->Name(), name)) {
+       //     if (boost::iequals(graph[*vit]->Name(), name)) {
+            if (graph[*vit]->Name() == name) {
                 vertex = *vit;
                 return true;
             }
@@ -104,22 +105,41 @@ namespace boss {
 
     void SaveGraph(const PluginGraph& graph, const boost::filesystem::path outpath) {
         //First need to extract vertex names, since their stored as private members otherwise.
-  /*      vector<string> names;
+        vector<string> names;
         vertex_it vit, vit_end;
         boost::tie(vit, vit_end) = boost::vertices(graph);
 
         for (vit, vit_end; vit != vit_end; ++vit) {
             names.push_back(graph[*vit]->Name());
         }
+
+        //Also, writing the graph requires an index map, which std::list-based VertexList graphs don't have, so one needs to be built separately.
+
+        map<vertex_t, string> index_map;
+        boost::associative_property_map< map<vertex_t, string> > v_index_map(index_map);
+        BGL_FORALL_VERTICES(v, graph, PluginGraph)
+            put(v_index_map, v, graph[v]->Name());
+
         //Now write graph to file.
         boss::ofstream out(outpath);
-        boost::write_graphviz(out, graph, boost::make_label_writer(&names[0]));
+        boost::write_graphviz(out, graph, boost::default_writer(), boost::default_writer(), boost::default_writer(), v_index_map);
         out.close();
- */   }
+    }
 
     void Sort(const PluginGraph& graph, std::list<Plugin>& plugins) {
- /*       std::list<vertex_t> sortedVertices;
-        boost::topological_sort(graph, std::front_inserter(sortedVertices));
+
+        //Topological sort requires an index map, which std::list-based VertexList graphs don't have, so one needs to be built separately.
+
+        map<vertex_t, size_t> index_map;
+        boost::associative_property_map< map<vertex_t, size_t> > v_index_map(index_map);
+        size_t i=0;
+        BGL_FORALL_VERTICES(v, graph, PluginGraph)
+            put(v_index_map, v, i++);
+
+        //Now we can sort.
+
+        std::list<vertex_t> sortedVertices;
+        boost::topological_sort(graph, std::front_inserter(sortedVertices), boost::vertex_index_map(v_index_map));
 
         BOOST_LOG_TRIVIAL(info) << "Calculated order: ";
         list<boss::Plugin> tempPlugins;
@@ -128,5 +148,19 @@ namespace boss {
             tempPlugins.push_back(*graph[*it]);
         }
         plugins.swap(tempPlugins);
- */   }
+    }
+
+    void CheckForCycles(const PluginGraph& graph) {
+
+        //Depth-first search requires an index map, which std::list-based VertexList graphs don't have, so one needs to be built separately.
+
+        map<vertex_t, size_t> index_map;
+        boost::associative_property_map< map<vertex_t, size_t> > v_index_map(index_map);
+        size_t i=0;
+        BGL_FORALL_VERTICES(v, graph, PluginGraph)
+            put(v_index_map, v, i++);
+
+        boss::cycle_detector vis;
+        boost::depth_first_search(graph, visitor(vis).vertex_index_map(v_index_map));
+    }
 }
diff --git a/src/backend/graph.h b/src/backend/graph.h
index 5f10b8e4..dac82c93 100644
--- a/src/backend/graph.h
+++ b/src/backend/graph.h
@@ -25,6 +25,7 @@
 #define __BOSS_GRAPH__
 
 #include "metadata.h"
+#include "error.h"
 
 #include <boost/unordered_map.hpp>
 #include <boost/graph/graph_traits.hpp>
@@ -37,6 +38,18 @@ namespace boss {
     typedef boost::adjacency_list<boost::listS, boost::listS, boost::bidirectionalS, std::list<boss::Plugin>::iterator> PluginGraph;
     typedef boost::graph_traits<PluginGraph>::vertex_descriptor vertex_t;
     typedef boost::graph_traits<PluginGraph>::vertex_iterator vertex_it;
+    typedef boost::graph_traits<PluginGraph>::edge_descriptor edge_t;
+
+    struct cycle_detector : public boost::dfs_visitor<> {
+        inline cycle_detector() { }
+
+        inline void back_edge(edge_t e, const PluginGraph& g) {
+            vertex_t vSource = boost::source(e, g);
+            vertex_t vTarget = boost::target(e, g);
+
+            throw boss::error(boss::error::invalid_args, "Back edge detected between plugins \"" + g[vSource]->Name() + "\" and \"" + g[vTarget]->Name() + "\".");
+        }
+    };
 
     //Gets the vertex for the plugin if it exists, or creates one if it doesn't.
     vertex_t GetPluginVertex(PluginGraph& graph, const Plugin& plugin, boost::unordered_map<std::string, vertex_t>& pluginVertexMap);
@@ -49,6 +62,8 @@ namespace boss {
     void SaveGraph(const PluginGraph& graph, const boost::filesystem::path outpath);
 
     void Sort(const PluginGraph& graph, std::list<Plugin>& plugins);
+
+  void CheckForCycles(const PluginGraph& graph);
 }
 
 #endif
diff --git a/src/gui/main.cpp b/src/gui/main.cpp
index bf465746..a0c65f81 100644
--- a/src/gui/main.cpp
+++ b/src/gui/main.cpp
@@ -604,21 +604,23 @@ void Launcher::OnSortPlugins(wxCommandEvent& event) {
         BOOST_LOG_TRIVIAL(trace) << "Adding in-edges for masters.";
         vector<string> strVec(graph[*vit]->Masters());
         for (vector<string>::const_iterator it=strVec.begin(), itend=strVec.end(); it != itend; ++it) {
-            BOOST_LOG_TRIVIAL(trace) << "Adding in-edge from \"" << *it << "\".";
             if (boss::GetVertexByName(graph, *it, parentVertex) &&
                 !boost::edge(parentVertex, *vit, graph).second) {
 
+                BOOST_LOG_TRIVIAL(trace) << "Adding edge from \"" << graph[parentVertex]->Name() << "\" to \"" << graph[*vit]->Name() << "\".";
+
                 boost::add_edge(parentVertex, *vit, graph);
             }
         }
         BOOST_LOG_TRIVIAL(trace) << "Adding in-edges for requirements.";
         set<File> fileset(graph[*vit]->Reqs());
         for (set<File>::const_iterator it=fileset.begin(), itend=fileset.end(); it != itend; ++it) {
-            BOOST_LOG_TRIVIAL(trace) << "Adding in-edge from \"" << it->Name() << "\".";
             if (boss::IsPlugin(it->Name()) &&
                 boss::GetVertexByName(graph, it->Name(), parentVertex) &&
                 !boost::edge(parentVertex, *vit, graph).second) {
 
+                BOOST_LOG_TRIVIAL(trace) << "Adding edge from \"" << graph[parentVertex]->Name() << "\" to \"" << graph[*vit]->Name() << "\".";
+
                 boost::add_edge(parentVertex, *vit, graph);
             }
         }
@@ -626,11 +628,12 @@ void Launcher::OnSortPlugins(wxCommandEvent& event) {
         BOOST_LOG_TRIVIAL(trace) << "Adding in-edges for 'load after's.";
         fileset = graph[*vit]->LoadAfter();
         for (set<File>::const_iterator it=fileset.begin(), itend=fileset.end(); it != itend; ++it) {
-            BOOST_LOG_TRIVIAL(trace) << "Adding in-edge from \"" << it->Name() << "\".";
             if (boss::IsPlugin(it->Name()) &&
                 boss::GetVertexByName(graph, it->Name(), parentVertex) &&
                 !boost::edge(parentVertex, *vit, graph).second) {
 
+                BOOST_LOG_TRIVIAL(trace) << "Adding edge from \"" << graph[parentVertex]->Name() << "\" to \"" << graph[*vit]->Name() << "\".";
+
                 boost::add_edge(parentVertex, *vit, graph);
             }
         }
@@ -638,12 +641,14 @@ void Launcher::OnSortPlugins(wxCommandEvent& event) {
 
         //Now add any overlaps, except where an edge already exists between the two plugins, going the other way, since overlap-based edges have the lowest priority and are not a candidate for causing cyclic loop errors.
         BOOST_LOG_TRIVIAL(trace) << "Adding in-edges for overlaps.";
-        boost::unordered_map< std::string, std::vector<string> >::const_iterator overlapIt = overlapMap.find(graph[*vit]->Name());
+        boost::unordered_map< string, vector<string> >::const_iterator overlapIt = overlapMap.find(graph[*vit]->Name());
         if (overlapIt != overlapMap.end()) {
             for (vector<string>::const_iterator it=overlapIt->second.begin(), itend=overlapIt->second.end(); it != itend; ++it) {
-                BOOST_LOG_TRIVIAL(trace) << "Adding in-edge from \"" << *it << "\".";
                 if (boss::GetVertexByName(graph, *it, parentVertex) &&
                     !boost::edge(*vit, parentVertex, graph).second) {  //No edge going the other way, OK to add this edge.
+
+                    BOOST_LOG_TRIVIAL(trace) << "Adding edge from \"" << graph[parentVertex]->Name() << "\" to \"" << graph[*vit]->Name() << "\".";
+
                     boost::add_edge(parentVertex, *vit, graph);
                 }
             }
@@ -653,11 +658,23 @@ void Launcher::OnSortPlugins(wxCommandEvent& event) {
 
     //Just for fun - output the graph as a ".dot" file for external rendering. If I can get this pretty, I might add it to a tab in the BOSS Report - here's a few Javascript libraries for displaying .dot files, but in my test case the graph is too complex and both libraries I found ran out of memory.
     //The .dot file can be converted to an SVG using Graphviz: the command is `dot -Tsvg output.dot -o output.svg`.
+    BOOST_LOG_TRIVIAL(trace) << "Outputting the graph.";
     boss::SaveGraph(graph, "output.dot");
 
-    //Now perform a topological sort.
-    boss::Sort(graph, plugins);
+    //Check for back-edges.
+    try {
+        boss::CheckForCycles(graph);
+    } catch (boss::error& e) {
+        BOOST_LOG_TRIVIAL(error) << e.what();
+    }
 
+    //Now perform a topological sort.
+    BOOST_LOG_TRIVIAL(trace) << "Performing a topological sort on the graph.";
+    try {
+        boss::Sort(graph, plugins);
+    } catch (boost::not_a_dag& e) {
+        BOOST_LOG_TRIVIAL(error) << e.what();
+    }
 
 
     if (!cyclicDependenciesExist) {