DL580 G3 & VMware 5.1 U1 - Enable 64bit OS Support & SAHF and LAHF support

Inherited three GL580G3's and all seem to be running same stepping CPU and BIOS.  On two hosts I can install and run (for a limited time to migrate VM's to other host) ESXi 5.1 U1 without issue, but on the third it won't install.  I get a PSOD that prevents the install  complaining about SAHF and LAHF support missing.  I have checked the BIOS on a working host and do not see any differences.

Thanks!

http://vsphere-land.com/news/what-is-sahf-and-lahf-and-why-do-i-need-it-to-install-vsphere-51.html

Thanks!