--- vdr-1.3.44~/thread.c
+++ vdr-1.3.44/thread.c
@@ -208,7 +208,8 @@
   childTid = 0;
   childThreadId = 0;
   description = NULL;
-  SetDescription("%s", Description);
+  if (Description)
+    SetDescription("%s", Description);
 }
 
 cThread::~cThread()