Hi. I just deactivated this extension today. It doesn’t stop checking on whatever site and couldn’t end an update process. Don’t know what’s going on. I have errors message upon surfing. Upadated NoScript extension successfully. Can somebody tell me what’s going on (updated to Comodo 3 final edition too today…) :o
I don’t use any of these active link checkers as they kill my dial-up bandwidth. However, whilst investigation some, I saw that some can pre-scan to deeper levels other than the first page, if that is the case, perhaps there are settings to avoid this deep level checking.
I deactivated, then restarted FF, then activated again and then restarted FF. The message errors are gone (downloading message error) but Robot Genius keeps not getting out of the checking mode!!! Just got an error message, it breaks my heart to get rid of it! 
The servers of Robot Genius were down. By mid-evening, everything was back to normal. It’s sad we have such “interruptions” or “discontinuities” of service for such security devices. But that’s internet… >:(
Hmmm… nothing to do with your computer or your applications.
Maybe you can use another ‘reliable’ service similar to it.