Hi, I was trying to use the trace.so extension module, but it was bailing out early with no explanation. I tracked it down to the fact that the system member of the trace_event_call structure no longer exists. It was moved up to the class structure. The change was introduced in this upstream commit: commit 8f0820183056ad26dabc0202115848a92f1143fc Author: Steven Rostedt <srostedt(a)redhat.com&gt; Date: Tue Apr 20 10:47:33 2010 -0400 tracing: Create class struct for events I don't have the cycles to fix this up right now, so I was hoping someone else would. ;-) Bonus points for printing useful error messages when the module fails to load for some reason. Cheers, Jeff