False cpu usage alarms

Hello

Using vcenter 5.0 build 623373 and esxi 5.0 build 821926.

I am getting many cpu alarms on windows 2k8 r2 OS's. But perf mon/task manager is consistently reporting normal or below average cpu utilization in the vm. These seem to be more frequent after a vmotion of a vm.

Alarm definition is set to (condition is above) (warn at 75 for 5 min) (alert at 90 for 5 min) (frequency repeat every 5 min) Even after acknowledging and clearing the alarms they come right back.

Thanks