The only thing I found was this:
The two primary causes of unusual behavior in Mozilla Firefox and Yahoo! Toolbar are:
* corrupt profile
* extension conflicts
Your user profile can become corrupt if the browser crashed or your computer halted unexpectedly. The following steps resolve many common problems with Mozilla Firefox.
First, update all your extensions and themes. Due to the large number of extensions that have been written for Mozilla Firefox, it is impossible to test every possible permutation and combination. Extension conflicts happen frequently, causing extension authors to release updated versions of their extensions as problems are discovered. If you have any Firefox extensions installed, check to make sure you have the most recent versions installed by doing the following:
* Select "Options" from the "Tools" menu
* Select the "Advanced" tab in the Options window
* In the "Software Update" section ensure that "My Extensions and Themes" is checked
* Click "Check Now" to check for updates for your extensions
* Install any updated extensions that are found
* Restart your browser
If you are still seeing problems, your user profile may be corrupt, or you may still have an extension conflict. Start Firefox in "Safe" mode from the "Mozilla Firefox" folder and see if the problem persists. If yes, you need to create a new user profile.
If the problem does not persist, you are most likely suffering from an extension conflict. Uninstall the extension you most recently installed and see if the problem persists. Typically, the problem will disappear and you should report the bug to the extension author.
(Found from
Yahoo! Help - Toolbar)