Problem with infrared keyboard+trackball

Hi,

I posted this message in microsoft.public.windowsxp.hardware but no
answer. Maybe here I will be more lucky:

I own one of these infrared keyboards that include a little trackball
in a corner (to use like a mouse). The infrared receptor is attached to
the PS/2 keyboard and mouse connectors.

I can use the keyboard and access the bios, I can choose the OS to boot
in the Boot Magic menu, but when XP has been loaded, it is, at the
Login screen, the keyboard+trackball doesn't respond and remain
disabled even if I reboot the computer. Then I have to attach a normal
PS/2 keyboard to acces the bios and exit saving changes to force the
bios to detect the Infrared keyboard. But every time I try to load
windows the keyboard is dissabled.

I have two computres, both with Win XP SP2. In one of them the
keyboard+trackball operates correctly but in the other one I have that
problem.

I tried to create a new partition and install a new windows XP SP2 but
the problem persist.

Does anybody known anything that I could do to find why Windows XP is
dissabling the keyboard at the startup?

Any help will be wellcome. If there is better place where I can make
this question, please, tell me.

Thanks in advance.