EN SFF wont boot with keyboard in..?

Hi all,

Newbie to this forum and I need help with a confusing problem.

I have just converted a P3 1 Gig EN Sff with a tv out card for use as a
media pc. I have bought an Acer Airkey IR wireless keyboard for it. With the
keyboard and mouse connectors plugged in (both go to the IR box) the PC will
not boot. It wont even start the POST. It powers up but just stops. If I
pull the mouse connector out and reboot - it POSTS and loads XP. I can put
the mouse connector back in after the memory starts counting and all works
fine from then on..... Until the next reboot!!

To clarify, the mouse and keyb ps2 connectors have 2 foot pf cable that go
into the IR receiver box that sits on the pc. The keyboard then sends to the
ir box..

Anyone any ideas??

Cheers ;o)