I have had the same issue while attempting to perform the install on 2 Dell 64 bit AMD machines. After selecting install from the main menu, I see the menu asking me to select my default language, but at that moment, the keyboard becomes non-responsive. A weird trait I noticed is that the numlock light goes out, and if I push the numlock button, the numlock light comes on for a brief moment, then turns right back off. However, I was able to perform a successful install using the same DVD to two Dell Intel based servers, no keyboard problems at all. In all cases, I used the same USB keyboard as none of my machines have PS2 ports.
Hopefully someone will figure out the cause of this soon, as I would love to upgrade from 3.2 to 3.4.