Trouble With Pokemon Crystal On Android, Using "Tiger GBC"

Ok, so I've been having issues with the Pokemon Crystal I recently got from EmuParadise. As far as the game itself goes, it runs great and everything. I'm running it on my Droid X, using the Tiger GBC app on the Android Marketplace. When I go to use the built-in Gameshark that comes with the emulator though...It won't work! At all! I've tried everything, from looking for a "master code" that some games have or even trying to reboot (both from save states or the built-in game save feature), to no avail. For reference, I've been playing Pokemon Yellow with the same emulator and everything: the cheats work fine. Anyone have any particular ideas or solutions to this problem?

P.S. Yes, I have tried contacting the creator of the app, to no luck as I've yet to hear from the chap yet.

Thanks in advance!