I take it you are still having problems with Firefox?
Let's try a reinstall from scratch.
We need to remove your Firefox profile data and settings. Before we do this we want to backup your bookmarks.
To back up your bookmarks:
In Firefox go to History > Show all History > Import and Backup (toolbar along the top) > Export HTML... and save it to your desktop.
Later when you re-install FF you can reverse the process and Import HTML... when the Wizard comes up just import the HTML file you had saved earlier.
Go to the link below for instructions on how to remove Firefox:
Look under the heading On Windows
Follow the instructions there On Windows Vista and in particular follow this instruction - see the bolded part:
Starting in Firefox 3, the uninstaller includes the option, "Remove my Firefox personal data and customizations". This will also remove your Firefox user profile data (bookmarks, passwords, cookies, extensions, preferences, etc.).
If the uninstall fails, as it may in some cases, continue on with the rest of the uninstall instructions.
Once you have remove Firefox entirely then download a new copy and re-install. After that, follow the instruction above to import your bookmarks back.
Firefox may be downloaded from Here.