Shows missing after dd?

My HR10 (250GA + 200GB) has been a little flaky lately and when I did a diag. on the A drive, not only did it fail but the drive made some "unpleasant" sounds during the check. I decided to dd it to a new (checked out clean) 250G drive- same mfgr, slightly different model #. To avoid problems, I did the dd with:
dd conv=noerror,sync if=/dev/hdc of=/dev/hdb bs=1024k
(dma was on for both drives)
I saw no errors during the dd and the Tivo booted up ok on the new dd'd drive, but every other show was missing- i.e. in NP but not there when I attempted to watch it.
So, I ask:
1. what's going on here (bad A drive, bad B drive, bad dd, etc)?
2. assuming a bad A drive (no way around this), I want to watch or archive all shows on the A drive (which I assume were the one's not viewable in NP), so how do I see which shows are stored on which drive?