Again, thanks.
This disc was good and the drive was good.
After uninstalling and installing the game it now works again. After about 15 seconds it goes from the disc screen to the loading screen and all seems well - for now <hopeful smile>.
Maybe deleting the copy protection folder helped <broader smile>. I hate pirates as much as the next person but hey - I did just buy the game today - have the receipt to prove it - so that folder is history (I assumed it would wreck something and I'd have to reinstall but that didn't happen).
