Trouble shutting down/logging off

Hey,

I've been having trouble shutting down/logging off/rebooting my 2010 Macbook pro for a while now. Most of the time if I try doing any of the above it just won't work and I get an error message coming up after 20 seconds saying that there was a problem quitting a certain application (this can be anything, skype, mail, safari, etc etc) and that I should force quit them. I've tried this force quit, but it doesn't help.

I've tried repairing the disk permissions using disk utility and onyx, but this didn't help.

I've even tried completely wiping and re-installing Snow Leopard, but again the problem seems to persist, and it means if I want to shut it down, I have to hold the power button for 5 seconds...

Anyone got any suggestions or experienced the same thing? it's out of warranty now, so not much point taking it into the Apple store...

 

I haven't tried either of those, but I will, thanks.

Any idea why it might be doing it?

 

Neither of those work, just tried them

Activity monitor shows that everything is quit properly, and holding the option button doesn't seem to do anything either.

Any other thoughts?

 

None, it's empty...