Well,
this thread might be the one... (I tried searching for the newest upgrade number).
I also found
some complaints about the newest B&N desktop upgrade at the B&N forums.
Finally, I also found this note that said the B&N eReader Desktop software will soon be renamed (
first post on this thread).
So now I'm just googling to see if there are any other definitive comments about what changed. I'm wondering if what I saw before was saying that then new software won't read the eReader PDB files any more (which ties in to the complaints thread). Still not sure...