Well, basically, if you create a new user, the new user will have an entirely new set of preferences. If the new user can run the App, then perhaps removing your preference files will allow you to run it.
About a week ago, I upgraded AIM for one of my sisters. However, running the application would allways result in 'unexpectedly quit' when she would log in to aim. I logged in as myself (instead of her) and the app worked fine. So I removed the aim preferences from her ~/Library/Preferences/ folder. But that didn't do it. So instead I moved the entire Preferences folder for that user to 'Preferences.old'. Then she logged in. The Finder automatically created a new 'Preferences' folder for her, and aim now works. I have no idea which preferance was troubeling aim, but removing them all did the trick.
So, if creating a new user allows the new user to run PB, here's how you can zap your prefs:
In the wonderful terminal:
cd ~/Library/
mv Preferences Preferences.old
then exit the terminal
log out
log back in
see if it works.
don't bother doing this if your new user can't run PB.
