My Diablo install of Fuelpad had similar results on my N800 when trying to import (had to reflash) my fuelpad.db from external memory card. I kept getting 0's in columns. For now I'm maintaining a CSV at home but will attempt an import again somewhere down the line-either after a couple more updates are released or I get tired of remembering to enter on the PC.
apt-cache show fuelpad|grep Maintainer
Otherwise, really enjoy the application and find it essential for my personal interest in record keeping.