First.. The version you mentioned (7.0.07777) is actually 7.0.0777...
Second... To check what kind of plugins you have installed you could do that 2 ways:
- You open a conversation, go to the Plus! menu and go to Plugins and tell us what you see there
Or
You go to the Plus! preferences, go to Plugins (The button at the bottom) and if you have plugins installed they show up there..
If I well understood: Your MSN signs in but is hanging on the "Signing In" window?
If so: Signing is is slower in MSN7... You could try to Patch it up to 7.0.0813, as it's reported being "faster".
You can find a link on the Messenger Blog at:
http://msnblog.stuffplug.com
Good luck!
Ow and.. "MSN Plus" is something by Microsoft... The name of the MSN plugin you are using is MSGPlus (As in: Messenger Plus)
/ 
