MobiDeDRM.py Error: no key found. maybe the PID is incorrect

[anonymous1234]

The error is "no key found. maybe the PID is incorrect". I found where someone else had the same error and it was suggested that they download to a portable device and use that pid. I tried that too and got the same error.

If I put single quotes around the pid it says invalid checksum. I have tried it on 2 different computers using both pids and downloaded them to my blackberry and used that pid and get the same message every time. On the ebook seller's website all three pids are listed in my account.

These are all free books that I downloaded to test a different ebook website before buying from them. I just went back to a previous purchase from a different retailer and redownloaded and did that one and it works fine.