Hi,
5.1.x release has two bugs which are right now just a history...
First was PSOD on 5.1 hosts configured with PCI pass-through
http://kb.vmware.com/kb/2039030
Second was related to USB controllers (PR979390):
http://kb.vmware.com/kb/2062310
Both fixes are included in 5.1 U2 release (build:1483097)
Message was edited by: vNEX