Can you both tell me what version of SA this is please? Click just to the right-of the icon and select About.
It's possible the new version 3 has reached you and I don't know too much about it's issues as it was hitherto only available with the beta products.
I do have it on my beta test rig but don't have this high usage issue.
You can probably get better answers than I can give by going the Technical Support Chat route - link at top left of the page, or even by using the SA Feedback Form:
http://www.siteadvisor.com/userfeedback.html or email [EMAIL="support@siteadvisor.com"]support@siteadvisor.com .