Problems with SC1430

Running Netware 6.5 SP 6 on this server.

System had been running fine for months until about a wee ago. No changes had been made to the system when this started.

In event log, showing CPU Protocol Error, and NW abending with Machine Check Error sometimes. Got a new processor through support, and installed it early this morning. Now, it has given another Machine Check Error abend, and CPU Protocol Error. Runs fine between these problems, but sometimes takes a while to get it back online (errors again when restarting server). It was running for 4 days with no problems until this today. Seems errors are intermittant...

Any ideas on what is causing this, and what to check now??