THANK YOU, THANK YOU all for the suggestions. My underlying problem turned out to be a hardware issue. The Ethernet drop had failed, and corrupted some files, including Microsoft FRAMEWORK NET 3.5 and FRAMEWORK NET 4 client, on its way down. Of course, it took days to isolate that because the machine worked intermittently, and I was thinking video card failure, then software failures first.
In and around all of that, I had uninstalled / reinstalled Calibre completely, deleted the suspect registry keys for displaying window positions, and upgraded my OS to Win 7.
Calibre 7.42 is VERY zippity fast in Win 7, and all features are working brilliantly. I love the metadata editing windows and features in the new version.
Thank you again for the suggestions.
