High CPU Usage

(I also posted this question at Wilders...)
 
I'm new to WSA AV so please bear with me if this may be a known issue.

I'm running the AV at the default settings except for electing manual scans and adding the apps I wanted to be protected within Identity Shield.

For the most part the AV has been running pretty smoothly on my system alongside the other real-time apps in my sig.

I've noticed, however, that yesterday morning and again this morning while browsing sites that I visit daily and that are in no way questionable, that the CPU reading in Task Manager was 75-80% or so. I already knew that something was amiss as the fans on my 17" desktop replacement were screaming bloody murder.

I had to shut down and reboot and then things were okay again both yesterday and just now.

This incident has now occurred both with and without WSA AV being excluded within MBAM and OA.

Any ideas what could be setting this off?

I can't say that it occurred at exactly the same time but I'd guess the time was pretty close. I can say that I was not on the same site when the incidents occurred.

Thanks for any help. Running XP Pro SP3.