Sorry for that confusion there. The 2059s are occurring on the MQPUT calls, but not every time, and in what seems to be no pattern whatsoever. The client actually doesn't reside on the N ...
It's a strange one, Charlie Brown. I have two Windows 2000 NT servers (MQ1 and MQ2 QMGRS) clustered with a cluster queue on OS/390. MQ Client and Server 5.1/CSD06 on the NT machines and all updates ...