Processing power limitation

I recently decided to come back from a 3 month hiatus from wow and start boxing again. The computer I box on is a laptop and I 5 box. Before I took a break everything was just fine with regards to my computer being able to handle 5 wow's. Now, however, my processors are being maxed out at 100% when I open my third wow. I have not made any hardware changes to my computer and have tried changing the Core affinity both manually through the task manager and through Keyclone but neither helps. I have set all of my Wow's video preferences to min. and have played around with changing them from 'windowed' mode to regular. The only real explanation I could come up with is if my computer did not change then Wow changed in those 3 mo. Have there been reported problems like this with any of the recent patches?

Processor: Intel Core 2 Quad Q9000 2.00 ghz

Memory: 6gb DDR3 (5.75 usable)

SSD

OS: Win7 64bit.

Would it do any good to reinstall Wow? Reinstall Windows?
Thoughts?

In one of the recent smaller patches, since 3.3, they announced a change where warcraft will use as many cores as your processor has, instead of only 1 or 2 cores.

That's the only change I can think of, which relates to cpu cores.

There was something you could change in the Config.WTF file to revert to the previous behavior. I'd check the patch notes, for the most recent patches and see if that fixes your issue.

http://www.wowwiki.com/CVar_processAffinityMask

Thanks. I seem to have got it solved. Thanks for the input. Now to address the low FPS issue Im having.