Just in case anyone needs a cover, I was looking for a replacement and stumbled across an old motorola forums thread that said moto had discovered a flaw in the covers and would replace them.
Call 1-800-734-5870, option 4 for warranty, option 5 for other. Have your Hex format MEID ready, and after a total of about 20 minutes of talking and holding, you will have a new battery cover set to arrive in 4-5 business days. Pretty sweet.
Hope this helps someone.