Your Black QVC Model: PRD07T20WBL7 is basically the same as a WPDN "in a little balck dress" (only with a larger internal microSD card). If you want the Official Android Market installed on your PRD07T20WBL7, you could try kewlguy's SD card enhancements without altering your original FW.
I just got the same model from QVC and I'm having the same problem. At Android Market when I try to download, the site says I have no Android phone associated with my account. How do I associate my Pandigital Model: PRD07T20WBL7 with my account? Thanks for any help.
You will need to make sure you have no FW files on your internal microSD card and be able to install the enhancements from your external SD card. Wiki Instructions Here.