That's discouraging. It only happens on my most powerful computers with AMD Phenom II 6x 1035 & 1045 processors, never on my old sluggish XP computers where other apps slow down while the scan is underway.
It's been a while since this thread was active. It pauses when it has to unwrap a zipped/compresssed file, for one example. If it's an undue problem for you contact Technical Support via Useful Links at the top of the page...it's a free phone call or online chat.