We are getting abends on one of our 6.5 SP4 servers:

Abend 1 on P00: Server-5.70.04-0: Apparent memory corruption - Unable to lock the Volume Manager Registration Mutex
Additional Information:
The NetWare OS detected a problem with the system while executing a process owned by VOLMN.NSS. It may be the source of the problem or there may have been a memory corruption.

Any ideas?