The iFrotz author posted this on his page:

— Turns out the problem is that I overrode the UIkeyboardImpl class to customize word completion, and the keybaord stuff changed a lot in 1.1.1. I’ll try to get a fix out tomorrow, hopefully one that’ll work in 1.0.2 and 1.1.1.

http://code.google.com/p/iphonefrotz/