I too vastly prefer bing to google these days. Not only does it return more intuitively relevant sites uncluttered with all those phony spam keyword sites & google 'preferred' results, its image search is far more user friendly. Add in google,inc.'s notoriously arrogant contempt for users' privacy, & bing is definitely the go-to engine these days. However, FF inexplicably requires that its users manually download bing as an add-on & I am having the same problem as others here have previously noted. I also receive the "This XML file does not appear to have any style information associated with it" message with document tree. I did as a previous reviewer suggested & scrolled all the way to the bottom of the user agreement,alas to no avail. So I guess I am forced to either bookmark it or google for bing and neither option is as good as having bing as my default search as I would prefer. Can't wait til FF joins the 21st century and abandons its googlephilia; if our overworked & underappreciated mozilla developers would take a break, look up & take a gander at the real world now & then, they might notice that many of its users already did that a long time ago. It's ridiculous that users have to download the darn thing & even more ridiculous that the download is so troublesome & even inoperative for so many.