So, I had the agent working very successfully to monitor my SQL Servers. Our IT Admin went ahead and reconfigured our S/W services on the SAM server to run using a different domain account (rather than the Local System). However, now our Agent has stopped polling the SQL servers.
I can't see anything being logged in S/W or the Event Viewer on the SQL Server. Here is the message within S/W:

I've been told that I need the S/W services to run under this new account. Is there anything I should be looking at to allow the agent to access the SQL servers now? Is there specific permissions required on those servers?
Thanks!
ANSWER:
Found that the new Domain account (while having elevated permissions on the domain) was not a local admin, which is needed for WMI. Added them to the Local Admin group and it solved the problem!