For everyone that was having the freezing issue, I was able to reproduce the issue by not having the correct APN settings for my phone.
I've made a modification to the program so that it doesn't lock up anymore but now shows an error message on the main screen. You can get the new version at
http://www.tetherberry.com/v2/TetherBerry.jad. It should show version number 1.0.5.
The error I get when this happens is Tunnel Failed. If you get this error please confirm that you have your APN settings correct in the Options->Advanced Options->TCP. Also make sure that you don't have any IT Policies that are blocking direct connections. If you are not allowed to make direct connections with your phone, I can make it go through your BES but you will need a custom version for that at the moment and your BES administrator will probably need to allow a couple connections on their end.
I hope this helps the people that are still having issues.