Dan,

Thanks for sharing the URL, but somehow to get the latest ESXi 5.1 Update 1 .ISO file the page is not found https://vibsdepot.hp.com/hpq/custom/vsphere51U1 ?

Not Found

The requested URL /hpq/custom/vsphere51U1 was not found on this server.

However, I have created the combined .ISO file VMware-ESXi-5.1.0-Update1-1065491-HP-5.50.26.iso combined with the Be2Net drivers as well. It works for the HP DL 380 G6-7 servers.