Search the forums please:
http://shoutbox.menthix.net/showthread.php?tid=33195
You can try the JRNZLoader, but as far as patching the EXE it is illegal and I haven't seen any polygamys for the newest version.
We wont help any further because if you are not an official Beta tester then it is illegal to be using the software. I suggest uninstalling it and using MSN Messenger 6.2 until the final release of 7.
As you see we don't provide any help for MSN Messenger 7 so you basically are SOL if you have a problem with it.