Using an Oracle supplied example which simply loops performing a login/log off using olog/ologof we find the program hangs. Eliminating semaphores seems to remove the hang (presumably only one semaphore at fault). Seems to occur on all UNIX boxes. We've upgraded from 18.104.22.168.0 to 8.1.6. No problems in 22.214.171.124.0 but seem to recall a patch being supplied in 7.2 for a similar problem. Any ideas welcome.