Did you install a newer version of Ubuntu?
I have never had to specify the resolution for my screen, an LG L1953T, and it
has always defaulted to the proper value, 1280 by 1024. I've used it on two
different computers, with two versions of Ubuntu (Gutsy and Jaunty) as well as a
few other distros which I have run from a LiveCD or USB flash drive. Both
computers have Nvidia video cards.
I would be astonished if Linux sought out config files on /data.