I think other users might find this useful.
I just had a little fight with openSUSE 12.1 over getting my networked Lexmark C544dn printer to work. The printer is accessed as a LPD-server.
When I tried to add the printer using CUPS (i.e. http://localhost:631), I got the error “unable to get list of printer drivers”.
CUPS’ error log showed several messages of the form “[CGI] Missing NickName and ModelName in …”.
All the files reported in those messages were from /usr/share/cups/model/manufacturer-PPDs. On a hunch I backed up and removed the complete manufacturer-PPDs directory. After that I could configure the printer.
A second look showed that all the PPDs mentioned in CUPS’ error log were from the package manufacturer-PPDs.
I deleted the printer again, restored the manufacturer-PPDs directory, and removed the package manufacturer-PPDs. After that I could add the printer without having to remove the manufacturer-PPDs directory first.