I have SCVMM 2012 running on as a hyper-v vm, and monitoring 22 Hyper-V hosts, 4 of which are clustered together.

When viewing the hosts in SCVMM, some of the non-clustered hosts say "Needs Attention" in the Host Status column, but I can't figure out why they need attention.  The health status for the effected hosts is OK, and I can refresh the hosts with no problem.  Where can I look to find out why the host status is needs attention?

I was able to get that Needs Attention message to go away by updating the agent, even though the health status did not show any error with the agent version.

I'm having the same problem - what do you mean by "updating the agent"

What Kenneth means by "Updating the Agent" is:

Within the Fabric  view, locate the affected host within the hosts pane/window on the right, right-click and select "Update Agent".

After this has completed, just hit refresh and the status should revert to OK, assuming that there were no problems to begin with.