Wordpress 3.1 permalinks 404

Just to let you know that, despite the fact your claim here:
https://premium.wpmudev.org/project/members-directory
Works perfectly with WordPress Multisite 3.1
This plug just messes a LOT with WPMU 3.1.
It totally brokes the category links.
POC:
- install 3.1
- install the infamous plug
- activate
- click on a category link ( /category/something/ )
- Voilà: 404 page.

Revert:
- deactivate the plug
- go to admin > permalinks
- resubmit same config
- category goodness is back.

This made me lost 5h and a lot of sweat to find out, plug-by-plug / each time resubmitting permalink config to find out that.

Global Site Search plug brings the same issue!