This is a discussion on Twitterific not working on my iBook G3 within the Apple Software products forums, part of the Tutorials category; So, I had Twitterific working on my eMac, but when I got my iBook and installed Twitterrific on the iBook, ...
Have you tried tweetdeck or any other apps?
Do they work?
If it doesnt it may be a problem with your network settings (had a problem accessing mobileme mail once...)
Try reinstalling tiger