So that glibc patch didn't help. So far all that works is turning off vmx support, or upgrading to a newer glibc, but that may just be a timing change. Running with efence takes a long time, but makes the problem go away and hence detects nothing, making me again think that is a timing issue. It seems somehow the different threads are managing to clobber each other when the vmx code is in use. -- Len Sorensen