The same problem here guys. It's very strange.
I managed to ensure, that messenger plus causing it and it's irreversible so far.
The problem remains and after the total uninstallation of plus.
I tried to uninstall msn 7.5 too and install live messenger but didn't solved
The strange thing is, that i've been using messenger plus for about 3-4 months all the time and it first happened 4 days ago.
I also formated my windows,i even changed the windows setup (i have 1 windows xp pro english, 1 greek win xp pro) but the problem is the same...
I have to say, that sometimes, when uninstall and reinstall messenger plus and msn 7.5, the personal messages starting to appear again but by the next restart of msn, the problem begins again