What HintOfLime said...
I never check PMs, emails anything- haven't done for the last 5+ years, emails/messages should be pushed, the whole idea of having to manually check for that is ridiculous in 2010. The PM system on here is the worst one I have ever come across in any software, no notification, if you check manually it shows you all your PMs ever cos you can't delete them, they are in backwards order so you have to make more clicks to get to the most recent, then when you try and open one it creates an error, so you have to click back and do it again.
Really isn't worth the bother.