Roomfinder updates the already choosen roomlist when making a new selection

Hi Community

I have an issue with the roomfinder in Outlook 2010. When I'd like to choose a room from a list, it works fine to show them and when I select on of them, the ressource gets checked in the left site list.

But when I'd like to add a second ressource (second room for this workshop) into the reserved rooms and I change therefore the roomlist in the roomfinder, it deletes all my selections I did in the left site list.

Is there a way to work around this?

Thank you very much!

Alex