Previous version iTalk worked for iPhone 3GS. Although I was able to record 2 hours continuously, there were the occasion drop outs and glitches in the sound.
The recent 4.5.1 has a serious bug and will not initiate the program at all on the 3GS. Ive experienced the exact same problem on the free version as well. Probably the result of very poor programming and QA testing.
Another loonie (dollar) wasted. Look elsewhere for a more reliable recorder.
Go West about iTalk Recorder Premium, v4.5.1