My issues come in a bundle, and are either present or not present, depending on the latest update. The issues first appeared at the start of the period of rapid updating insanity (which came very close to driving me away from Firefox). The problems stayed consistent through a number of updates over a number of months, and then were fixed. They then reappeared a number of months ago. Sorry I have not been tracking the specifics of which version they are associated with more carefully. I am currently running Firefox 12, on Vista Home Premium, Service Pack 2. The bundle of issues involves: - not being able to open more than one instance of Firebox at a time (consistent) - after closing Firefox, not being able to re-open the program without re-booting my computer (intermittent) - if I quit Firefox with media playing from a website, sometimes the media keeps playing in the background, with no means of stopping it (intermittent) - add-ons are behaving erratically. When I open Firefox I never know which add-on icons are still going to be in the toolbar. When I go to put them back in the toolbar, the icons are not available in the Customize menu. I also sometimes cannot open the Add-ons page under the Tools menu. When I can open it, the relevant add-ons are listed as "enabled". (intermitent) Any insight on how I can get Firefox running smoothly again would be greatly appreciated.