download
http://www.targus.com/us/Downloads/IRKeybd_v1_39.exe.
Run that .exe on your PC, to install the IRKeyboard drive to your x51v.
Use the file I provided 22Feb07.
Right click IRKeybd.ddb.txt and Save target as to your PC.
Rename IRKeybd.ddb.txt to IRKeybd.ddb.
Put this file in your Windows directory on your AXIM.
Copy and paste it into Windows over writing the original.
Make sure you uncheck Receive all incoming beams.
(Start -> Settings -> Connections -> Beam)
Soft reset. After reset you should be able to enable the IR Keyboard driver
There are other IRKeyboard.ddb files on this discussion. You could try using them. They remove all references to COM3 in the config file, which means there are never any conflicts with incoming beams. (I.E. not required to uncheck Receiving all incoming beams. ) See how Help -> About works in that version.