What would cause Arcserve 6.5 with all patches applied to lock up NT 3.51? The Backup process completes but does not release from memory. Next time it runs it locks up the server. The only way to remove it from memory is to reboot. Important note: This only happens with Dual processors enabled. It' running on a Tricord 3000 server. The processor boards, memory boards and backplane have been replaced. Windows NT backup creates the same result. Good luck!