Isn't it strange how these things all come together. I have just (by accident) updated iTunes and found that QuickTime had elected itself to open with all audio & video files. Control Panel / Folder Options was an obvious first call but QuickTime was still in charge. Eventually found some options in QuickTime under Edit/Preferences/QuickTime Preferences/Browser/MIME Settings which enabled me to shut it up. Two hours drinking time wasted.
Do these people think they are doing us any favours?
WTF is a MIME setting?