The folks at Dallas Summer Musicals have updated their website with the following note:

SINGLE TICKETS: are currently only available for Defending the Caveman (March 21 - 22, 2008 at the Majestic Theatre) and Menopause the Musical (March 11 - 16, 2008 at the Majestic Theatre). All Other shows will be available at a later date. To be the first to hear the on-sale dates, subscribe to eNotes!