DECthreads possible loss of signal

[Ian Kirkham]

I've a problem with a multi-threaded application on Tru64 5.1B using condition variables.
Very occasionally we arrive at a situation where a waiter (pthread_cond_wait) should be released by a signal from another thread but this doesn't seem to release.
The signals and waits are properly established in the context of the associated mutex. The application uses mutexes and condition variables in shared memory which slightly complicates things. We've seen this happen on quad cpus under heavy load but not reproduced this on dual processors.
I am in the process of trying to proove that this is the case.
Has anyone seen similar?
Regards,
Ian