Ok now its my turn. I hit the Generate Thumbnails menu but didn't realize all thumbnails were selected. I cancelled that action and did the following without luck

Closed and restarted AP. Deleted cache and preferences, Repaired Ap lib, Saftey reboot.

But every time I start Aperture it wants to generate 77,000 thumbnails. I can't get it to cancel that. Im down to my last tricks of Rebuild and fsck but I must already hold the record for rebuilding this week alone!