Hmm, i think i know what is causing it (but i dont have vista to test it) so...
Can you please maximize the window from the taskbar and tell me if you get the buttons back...
Window Manager is discontinued, for WLM try the new, Enhancer for contact list docking, auto-hide, hide taskbar button, remove button flashing and remember keyboard layout in conversation windows
Messenger Plus! Live Enhancer
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