Peter...
The problem was a registry key in a hive with only numbers to identify it. Since someone at a forum over at Tom's hardware gave me a 90 second instruction on how to track it down, edit the key and re-boot the PC, there has been no further instances of it in over 6 months.
Your reply reminded me of the mechanic who said I'd cooked the engine in my Audi when the water pump failed. He quoted me $6000+ to fit a new engine. The 'real' mechanic I went to for a second opinion actually knew what he was doing and fixed the problem (including replacing the water pump in 2 days for $480. The cylinder heads were warped. Nothing at all wrong with the rest of the engine.
Same with my inDesign problem. Nothing at all wrong with inDesign, just a 0 where there should have been a 1 in a registry key. Maybe my attitude does suck but finding someone who didn't have the throw it away and start again attitude saved me a lot of wasted time. Thanks for your suggestion and commentary. I'll remember it for a long time.