mamewah,mame84b + ipac to prob

[akira]

hello all, well ive managed to get my cab + controls built and now finaly starting to put things together  
everything works fine except for in mamewah and mame the shift function on the ipac isnt working, but all the joysticks and buttons work fine. mainly its for the 'esc' button to work so i can get back into mamewah.

iv tested the ipac in notepad ect and the shift functions work sound, so i dont know if its a prob in mamewah or mame itself.

my set up is-

winxpro
mamewah
mame84b
ipac2 (PS2)

cheers for any help
regards...