I have a ticket open with VMware for the same exact issue. They have confirmed that this is an issue with AMD procs and the NVidia VIB.
I also confirmed it works fine on my DL380 (intel). So if you have an AMD based server I bet thats your issue.
I've contacted NVIDIA for an update on the AMD issue....nothing yet.
I've also requested that vmware create a KB article on this until its fixed.
-M