Though SQL backup of the MSDE database is a good option, i think the veritas recommended option is to use its database maintanence option. backup exec manual (PDF document), clearly explains how to create database maintanence and recover
See page 475 for configuring database maintanence
Page 775 for Recover a media server database
However, its always good to test database and recovery once in 6 months, just to ensure that everything works fine.
hope this helps.