Internet Explorer: JPG will only save as BMP
The classic solution for this problem (which invariably works) has always been to empty your Internet Explorer cache, but of course this is a workaround, not a fix.
Well, it seems that the August Cumulative Update for Internet Explorer fixes this problem! So go get it guys 'n' gals.
http://support.microsoft.com/kb/896727
Be warned, this is not an 'all circumstances' fix. There are rare instances when the cumulative update, and clearing the cache, and other fixes on my site, will not work - rare instances the circumstances of which I suspect are not public so I cannot not discuss them here.