You have the rights, but you let them put it on a DVD if they want too. I don't think you have much to worry about anyway. When was the last time you went to Best Buy and bought a 6 minute film?
And every festival does it. At Slamdance you can buy anthologies of their shorts, etc.
It shouldn't hurt getting into other festivals (it's certainly not enough to count for IMDB) , plus we haven't gotten around to actually doing it in over 2 years.