Well, may as well start on a note of triumph. It’s been frustrating that my superduper iMac 27″ i7 hasn’t been working perfectly. Can’t easily boot into Windows 7, there have been occasional screen freezes, but worst of all I can’t watch videos I’ve recorded from the tv – the computer only recognises them as blank disks. But, problem solved! I’ve discovered that an old external dvd drive can happily do the job.