Shoutbox

I have some weird problem with MSN Messenger (version 6.20137). The tabs which should be displayed on the left side of Messenger have disappeared without any appearant reasons. I've tried the following:
-Untick and tick (now untick) This is a shared computer so don't display my tabs in Options on Privacy section.
-Restart, uninstall and reinstall MSN Messenger, with and without Messenger Plus!
-Contact Microsoft tech support, but even they seems to have no idea
-Did search (search engine) everywhere with no result

You can see the screenshot which I've attached here. BTW, the problem is not only with tabs, I can't also launch 'Fun & Games' in conversation window. The strangest of all is that it only happen to my account, if I sign-in under friend's account on the same PC, I can see all the tabs and all functions work correctly! Any help will be appreciated, thanks!