I have two HP Proliant Servers (DL380 G5 and ML 350 G5) with very similar BIOS. Both are VM Hosts and everything is working well on them. I cannot, however, configure USB passthrough. The options in the vSphere client are greyed out. I have seen postings that refer to BIOS options that should be enabled to activate this option but nothing in the BIOS looks right. VT is enabled.