Cassie16: I think your being paranoid. If your bagging and storing the mice correctly then there should be no weird taste, because no Oder or smell can get to any other frozen items. No contamination can happen..
I have had this happen to me.. I use to work at a pet shop, like three years ago, they kept canned drinks in the same fridge as the feeder worms. I also got so paranoid..that I though canned drinks tasted weird...
If it really bothers you, you could buy a smaller fridge/freezer to store them in.
There is always a chance I could be wrong...
-Hilly