Hello again Dave,
Do you also have Windows servers in your monitoring (can also be your SIM server)? Could you try to open the SMH page for a Windows server and do a test for WBEM event send? You can find this under Settings > Send Test Indication. Choose any eventype and look for these events in your SIM server under Events by Severity > All Events.
You can also check the WBEm proxy settings under Options > Protocol Settings > WMI Mapper Proxy. It should contain your server and the default port. The WMI proxy also has a logfile at c:\Program Files\The Open Group WMI Mapper\logs\PegasusStandard.log or the Error.log for that matter. Perhaps you can find the error there.
Kind regards,
Andrew