Tom - is this Drive Encryption for HP Protecttools? If so you need to be working with HP for support, as it's their product, not a McAfee product.
If you blew away the MBR though, you're not going to be able to use the safe decrypt options - you're going to have to use force crypt as long as you are 100% sure your sector range is good, and that you are using absolutely the correct HP recovery file.
HP should be able to help you more though.
Drive Encryption is HP Protect Tools. Unfortunately HP do not provide as great support as you do.
I did force encryption and it helps me 100%.
Thank you very much for your great support