Intel SR2200 server keyboard/mouse conundrum!

Ben Davison and I were installing a dual-server Avid Unity rig at MTV (it's the fail-over config with two Media Managers seeing the fibre array) - both servers, once rack'ed up would boot once and then never boot again (couldn't even see the BIOS screen) - if we extracted the machine from the bay it would boot fine - back in the rack and it would boot once then nada. Very frustrating - the fault was found to be the little PS/2 breakout adaptor - the SR2200 has only one PS/2 socket on the back and the breakout for mouse and keyboard isn't marked - if you get it the wrong way round (keyboard plugged into mouse hole etc.) it does the above - crazy considering the server clearly sees the keyboard and mouse on that first good boot!