This is the only log I get when the failure happens.
Attempting to sign in to messenger service using account: 'hcbuild@hotmail.com'
Failed to sign in to messenger, timed out while attemping to connect.
Retrying action (1 of 3)...
Attempting to sign in to messenger service using account: 'hcbuild@hotmail.com'
note that this also happens from our XP SP3 machine, so it isn't strictly related to Win 7, and I don't think it is a bug necessarily in 1651 (it happened in previous versions that were working, then stopped working)
I reported a similar issue with FB6 and the problem turned out to be "out of date msn library" - so I expect something similar is going on here. Any prospects on an updated library?