Google results problem with firefox addon

Question

I have written a firefox addon with which user can add notes to the pages they are viewing. Users can also highlight the content they like on the page. My addon adds some css and javascript files to the page once the document is loaded. The extension is working properly except with some google results pages. The results sometimes appear clustered. I found through firebug that google results page is adding some extra css rules (when my addon is present) which are messing with the results page. Does anybody know why this is happening? Here are the screenshots of the google results page when
a. my addon is disabled - http://i40.tinypic.com/m80hft.jpg
b. my addon is enabled - i41.tinypic.com/10zr7za.jpg

Thanks,
simil

Answer 1

It turns out that google keeps modifying the style elements present in the head. Moving my styles to the body element solved the problem.