Good Morning, I was wondering if anyone has seen anything similiar to this. We have two processes which are communicating via signals (SIGUSR1), these processes routinely block and unblock signals by using sigprocmask with SIG_BLOCK and SIG_UNBLOCK. After running for various lengths of time we see our signal handler called while the signal was supposedly blocked. Currently, we are running on a multi-processor (4 Xeon Processors) under Windows2000. The problem seems to happen more frequently if you run more than one copy of the test concurrently. We're currently running our test on a single processor WindowsNT 4.0 system, and have yet to see the problem. Has anybody seen anything similiar to this. Thanks, --Craig _________________________________________________________________ Get your FREE download of MSN Explorer at http://explorer.msn.com -- Want to unsubscribe from this list? Check out: http://cygwin.com/ml/#unsubscribe-simple