In case it might be useful in the future, here is what fixed hte problem.
I established another user account on my computer, and opened PS through that. The Detail/Sharpening worked fine. The defect was not present, showing that the problem was in my user directory and not in PS.
Back in the original account, I ran cs5cleanscript from Adobe.com to uninstall cs5 and all related files. It missed some, which I deleted, along with old files from previous PS and ACR found in users/name/library/preferences.
Reinstalled PS. It works.
You've taken the brute force approach, but it also works. If working from a different account worked, it would point to the preferences, so recreating them manually, rather than through the Cleaning script might have worked.