diff --git a/ChangeLog b/ChangeLog
index 311f396da4..127c6038f0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2008-04-14  Jan Schmidt  <Jan.Schmidt@sun.com>
+
+	* gst/matroska/matroska-demux.c:
+	(gst_matroska_demux_handle_seek_event):
+	Fix open-ended seeks in matroskademux
+	Patch by: Mark Nauwelaerts <manauw skynet be>
+	Fixes: #526557
+
 2008-04-14  Jan Schmidt  <jan.schmidt@sun.com>
 
 	* tests/check/Makefile.am:
diff --git a/common b/common
index bdc5172b0b..f88ff852da 160000
--- a/common
+++ b/common
@@ -1 +1 @@
-Subproject commit bdc5172b0ba183be6d92e58cb51782c23e9f2127
+Subproject commit f88ff852da7631ad2d0be835763da6d551a63883
diff --git a/gst/matroska/matroska-demux.c b/gst/matroska/matroska-demux.c
index b67d78c45d..2b0ea0324a 100644
--- a/gst/matroska/matroska-demux.c
+++ b/gst/matroska/matroska-demux.c
@@ -1397,24 +1397,27 @@ gst_matroska_demux_handle_seek_event (GstMatroskaDemux * demux,
   GST_OBJECT_LOCK (demux);
 
   /* if nothing configured, play complete file */
-  if (cur == GST_CLOCK_TIME_NONE)
+  if (!GST_CLOCK_TIME_IS_VALID (cur))
     cur = 0;
-  if (stop == GST_CLOCK_TIME_NONE)
+  if (!GST_CLOCK_TIME_IS_VALID (stop))
     stop = demux->segment.duration;
+  /* prevent some calculations and comparisons involving INVALID */
+  segment_start = demux->segment.start;
+  segment_stop = demux->segment.stop;
+  if (!GST_CLOCK_TIME_IS_VALID (segment_start))
+    segment_start = 0;
+  if (!GST_CLOCK_TIME_IS_VALID (segment_stop))
+    segment_stop = demux->segment.duration;
 
   if (cur_type == GST_SEEK_TYPE_SET)
     segment_start = cur;
   else if (cur_type == GST_SEEK_TYPE_CUR)
-    segment_start = demux->segment.start + cur;
-  else
-    segment_start = demux->segment.start;
+    segment_start += cur;
 
   if (stop_type == GST_SEEK_TYPE_SET)
     segment_stop = stop;
   else if (stop_type == GST_SEEK_TYPE_CUR)
-    segment_stop = demux->segment.stop + stop;
-  else
-    segment_stop = demux->segment.stop;
+    segment_stop += stop;
 
   segment_start = CLAMP (segment_start, 0, demux->segment.duration);
   segment_stop = CLAMP (segment_stop, 0, demux->segment.duration);