I've used BrowserTraySwitch for ages - great software!
Unfortunately, since installing Firefox 3 Beta4, it no longer lets me switch my default browsers between FF3 & IE6. It's kinda hard to tell since there are so many registry entries involved, but certainly it doesn't correctly change the URL shortcut association.
I've tried your suggestion of manually setting each browser as the default once, but that doesn't fix it.
One more thing: my config.ini file is empty - I'm relying on BrowserTraySwitch's auto-detect.
Any ideas on how I might fix this?