diff --git a/mozilla/media/liboggz/src/liboggz/oggz_seek.c b/mozilla/media/liboggz/src/liboggz/oggz_seek.c
index f933d4d..23ffb57 100644
--- a/mozilla/media/liboggz/src/liboggz/oggz_seek.c
+++ b/mozilla/media/liboggz/src/liboggz/oggz_seek.c
@@ -486,16 +486,18 @@ oggz_scan_for_page (OGGZ * oggz, ogg_page * og, ogg_int64_t unit_target,
       serialno = ogg_page_serialno (og);
       granule_at = ogg_page_granulepos (og);
       unit_at = oggz_get_unit (oggz, serialno, granule_at);
 
       break;
 #else
       do {
         offset_at = oggz_get_prev_start_page(oggz, og, &granule_at, &serialno);
+        if (offset_at == -1)
+          return -1;
         unit_at = oggz_get_unit(oggz, serialno, granule_at);
       } while (unit_at > unit_target);
       return offset_at;
 #endif
     } else if (unit_at == unit_target) {
 #ifdef DEBUG
       printf (" scan: (%lld) == (%lld)\n", unit_at, unit_target);
 #endif
@@ -552,16 +554,19 @@ oggz_seek_guess (ogg_int64_t unit_at, ogg_int64_t unit_target,
     printf ("oggz_seek_guess: unit_end <= unit_begin (ERROR)\n");
 #endif
     offset_guess = -1;
   } else {
     offset_guess = guess (unit_at, unit_target, unit_begin, unit_end,
 			  offset_begin, offset_end);
   }
 
+  if (offset_end != -1 && guess >= offset_end)
+    offset_guess = offset_begin + (offset_end - offset_begin)/2;
+
 #ifdef DEBUG
     printf ("oggz_seek_guess: guessed %" PRI_OGGZ_OFF_T "d\n", offset_guess);
 #endif
 
   return offset_guess;
 }
 
 static oggz_off_t
@@ -759,16 +764,18 @@ oggz_seek_set (OGGZ * oggz, ogg_int64_t unit_target)
     } else {
       break;
     }
   }
 
  found:
   do {
     offset_at = oggz_get_prev_start_page (oggz, og, &granule_at, &serialno);
+    if (offset_at == -1)
+      break;
     unit_at = oggz_get_unit (oggz, serialno, granule_at);
   } while (unit_at > unit_target);
 
   if (offset_at < 0) {
     oggz_reset (oggz, offset_orig, -1, SEEK_SET);
     return -1;
   }