We had the exact problem, vCenter 6 U2 (P03) with NSX Guest Introspection and TrendMicro.
The problem started after updating vCNS to NSX 6.2.4, VMware support didn’t know what to do.
After updating NSX from 6.2.4 to 6.3.1 and update the Guest Introspection agents – the problem resolved!
BTW - it also resolved some VUM problem we had but we don't sure if its related.