WP-MU 2.6 + Multi-DB 2.6 Oddity

Good morning.

I've upgraded WP-MU and Multi-DB to 2.6, and the upgrade process appeared to work, as I noticed database traffic to the multiple databases, etc.

The problem that came about though, is now accessing sub-blogs seems to have stopped working. It appears to be acting like the single primary blog.

The upgrade took place between a version of WP-MU and Multi-DB from a couple years ago, and the latest. So the changes between versions were quite drastic, as expected.

Are there any debugging tips I can follow to get this resolved?

Even BETTER, would be a program that I could basically dump the entire database from the old site and *properly* import it into the new system, users, blogs, posts and all. But I'm not seeing anything that handles this properly.