taskbar keeps freezing up

Hello There, I have installed Vista last night, that went quite well, although this is the 2nd time (I had to roll back to XP while waiting for a wireless card that will work with Vista).
Anyway my start button works, but none of the other icons on my taskbar works... On MSN if someone sends me a message, it comes up flashing at the bottom in the taskbar, but I cant click on anything...just gives me a 'ding' noise.
Can anyone please advise...
Thanks