I got to help you out.
Did your friend use the Get all Three Starters code on his gameboy. If he did, I know what the problem is.
That code not only controls that but also 5 other things about the game, including the Trade/Battle Machine.
Tell him, if he did this, to change the code from 0100XXXX (where XXXX will stay the same) to 01FFXXXX. I am using the X's as I don't recall the code right now. That should reactivate the Trade/Battle machine.
Email me (in Sig) if any problems with the codes occur.
Visit my Team Strategy Page on my Gameshark Site:
Matt's Shark and Team Strat Page
Have fun and make yourself at home.