Just upgraded to Live Messenger 2011 and Plus! 5

In previous versions minimizing live messenger to the notification area (by selecting close ( X ) ) would minimize both messenger and the event viewer window. Likewise restoring messenger, restored both messenger and event viewer - they were tied together!

In the new version - action on the messenger window does not affect the event viewer window - they are no longer tied.

This means that the event viewer window cannot be minimized, only closed (or full-screen). Doing this means you have to re-enable the event viewer window every time you resore the messenger main window!

NB. When using multiple messenger instances - the event viewer window, for the active messenger window, is brought to the front!

It works perfectly in Windows XP and WLM 2009 though....

Are you by any chance running Vista or Windows 7?
EDIT: hmmm, obviously because you are using WLM 2011

EDIT2: either way, what are you running? Vista or Windows 7?
Because I think it could have something to do with how WLM 2011 "minimizes" (or rather not minimizes for that matter) in the new OSs. The lack of the tray icon  when you press the X (close button) is also related to this. It's how the new OSs work.

But yeah, I agree that the Event Viewer should at least 'mimic' the old behaviour in that case...

Oops forgot to mention OS - yes Vista SP 2

Edit - Don't know about the minimize to notification area problem - think that relates to Windows 7. Never had problem with vista (same as XP in that respect)