When I open Firefox 4 I always get this: Script not working Script: chrome://tavgp/content/libs/include.js:595
also when I go to close Firefox4 it does not release from processes I have to ALT, Ctrl DEL to end process. This happens EVERY time Iuse FF4.
Do you have AVG Safe Search? Try disabling it.
I have the same problems on some sites. I just tell firefox to stop running the script it usually is just an add anyways.
I also downloaded a program called pskill, you can stop any program that is not closing (like firefox does to me also) with it. Follow the instructions they give you. You can use it for any program.
Start Firefox in Troubleshoot Firefox issues using Safe Mode to check if one of the extensions is causing the problem (switch to the DEFAULT theme: Firefox (Tools) > Add-ons > Appearance/Themes).