[OT] screw threads in Jornada 680

I bought one of those Dutch Railways refurbished Jornada 680s 
available in the US from Tigerdirect and a few other places.

http://www.tigerdirect.com/applications/SearchTools/item-details.asp?EdpNo=1163978&CatId=228

This has an extra cover on the bottom which prevents access to the CF. 
It can be easily removed with a Torx screwdriver, but one of the 
screws also holds down the keyboard on the left side. With the cover 
removed, the screw is too long to put back in, and the keyboard is a 
bit floppy.

Does anyone know what thread that screw is? I need to get a shorter 
one. Is it a standard metric thread or a special purpose thread of 
some sort? Anyone know where I might find that screw?

Thanks,
Mike