Windows Service Monitors not responding

Hi,

We have a couple of new servers that I am wanting to put into OpManager; I have set them up and they seem to be pulling back data etc all fine.
Specifically I was wanting to monitor a Windows Service (SQL Server Analysis Services / MSSQLServerOLAPService). So I discovered the services (using the wizard) and selected the service, associated it with the device. All looked fine.
Status is green. No troubles.

So I tested it. I stopped the service, pulled the polling interval back to 1min and waited for about 5 min. Going all over the show in case it was a refresh issue; but no. Never did it give me any indication that there was anything wrong.

Any ideas what might be going astray here?

Running version 7204

Thanks in advance for any assistance.

Cheers
Troy