Any issues with multi-db?

I run the multi-db from wpmu on all of my sites. (creates 256 databases for each site).

Are there any known issues with your plugin and multi-db?
*I find for the most part I don’t have issues, but anytime a plugin deals with optimizing the db, cleaning it, etc, I have to be pretty careful.

http://wordpress.org/extend/plugins/wp-cleanfix/