The web site is almost back to normal now. WPG2 seems to work fine. I just needed to run the updater for Gallery 2 again with WPG2 and the vSlider3 theme (Gallery 2 version) deactivated. I then reactivated WPG2 and the vSlider3 theme in Gallery 2, and the integration started working again.
For some reason, the light box plug-in no longer works correctly in Gallery 2. Also, the description bubbles on the Gallery 2 version of Google Map (which shows a photo thumbnail when you hover over the map pin) also seem to have some formatting problems. Perhaps I’ll find solutions in the coming days.
I’ll post a longer version of this story later, but it seems the WPG2 plug-in for Gallery 2 is not compatible with WordPress 2.9.2. I decided to upgrade to that version, and now the headaches have begun. I’ve had to deactivate my Gallery2 gallery for now until I can come up with a better solution.
Well, the new blog and gallery are up and running. I’ve probably spent four or five days of effort during the last three weeks getting WordPress and Gallery2 to play well together. The trick has been the WPG2 plug-in and the vSlider3 themes. They’re not quite perfect, but they give the site a level of integration that would have taken me weeks to figure out.