I seem to have at least temporarily fixed the issue on my iPad. Basically I deleted the iPhoto app on my iPad. I was then able to sync any photos I wanted. Possibly iPhoto on the iPad and iTunes share some direcotry information and that somehow interferes with syncing.
The complete steps to my temp fix:
- Deleted iPhoto on the iPad
- Synced my iPad so that it removed all my photos
- Deleted the iPod Photo Cache
- Synced my iPad with the photo folders I wanted to import. I started synching one folder at a time and when that appeared to be working, I synced all the rest. All the syncs were sucessful.
- Re-downloaded iPhoto to my iPad. When I started iPhoto it did it's "build database" thing, and that all worked and I could view my photos in iPhoto.
So I got all my photos on my iPad that I want. Time will tell if iPhoto for the iPad and iTunes will continue to have issue with my new iPad -- whether I will be able to sync without losing photos, or to add additional photos or folders.