Multi-DB with Ultimatum Theme

Hi,

We have a multisite using Multi-DB and at the same time would like to use ultimatum theme http://ultimatumtheme.com/. After activating the theme, an error showed up saying "No Database Selected". Their developer said

You are using a WPMU.ORG Drop in which replaces original WP Database class called db.php and this makes impossible to run queries through Ultimatum.

Is there any way we can use multi-db with ultimatum theme?

Thanks