Shoutbox

Hey all,
Sorry if this topic has been brought up before, but I couldn't find it. Nonetheless, I've just finished installing Windows XP 64 bit edition RC2 (build 1433), and naturally, one of the first things to be re-installed was MSN 7 & Messenger Plus.. Problem is, it seems I'm unable to run MSN Messenger whilst Messenger Plus is running, as it just crashes and brings up an error message.
Just curious as to whether anyone else has experienced similar problems, and is there a fix for it?
As I stated, I'm running XP 64 RC2, MSN 7 build 0604, and the beta of Messenger Plus 3.40 (or whichever version was released on the forums here a little while ago).
Any help on this matter would be greatly appreciated.