Ok, realized what was going wrong for me. You have to be out of airplane mode for the covers to come in since they are being downloaded from Amazon. Duh!
Note that I copied the mobi file to my documents directory via USB rather than using the network. I'll try to transfer the same files via Calibre to see if that really does trash the results. If it does, I suspect something is wrong in the cover copy. It would be nice if there was an option to NOT copy covers - I have googled and did not find such an option if it does exist.
EDIT: Another thought is that I use the option to rename my books on the fly to include series information when Calibre moves them to my Kindle. I would not be surprised if that is stepping on the AISN fix.
Last edited by Greg G; 10-10-2012 at 02:39 PM.