When I upgraded to 4.0 my AV program AVG stopped updating a tab that is called "Page Status" it used to scan the page and give me a color coded message, Green = good Yellow= Questionable, Orange = Risky and Red = Dangerous. After updating to FF4.0 it is always grayed out and always stays gray. IT gives me a message"Please wait a moment we are checking this website just now...." and it never changes. I tried "cough cough" IE7 and it worked just fine.

I did an uninstall of FF4.0 and reinstalled FF3.5 and it worked also. So, I uninstalled FF 3.5 and did a reinstall of FF 4.0 and the problem persists.

I guess I will go back to 3.5 until there are some updates and maybe it will address this problem.........