Well, that explains that message - when you do the initial startup and customise.xml runs it sets up some GDFS variables, so you are seeing the values from the K810 firmware.
All I can suggest is to try reflashing MAIN, FS and the custom pack (using the original K800 firmware) and see if that works - I presume the GDFS backup was made at a point when the phone was working correctly?
If you can't get it to flash, try another file, on the chance that the firmware package is corrupted...