CPU occupation problem Rated 5 out of 5 stars

This add-on is extremely usefull, thanks a lot. I have been using it successfully for some time.

But with the current version 3.1.8 and Firefox 7.0.1 on windows XP SP3, I have a big problem : when asking to display the page with modifications it takes around 90 seconds with very high CPU usage that blocks Firefox and even other applications.
Can you have a look please ?

This review is for a previous version of the add-on (