My Win98SE old-games machine has a Samsung 40GB drive in it, which it sees as a 20GB drive. So resize the partition, you'll tell me... and that's exactly what I set out to do (despite not remembering setting up a half-size partition) when I connected it to my main computer (running Kubuntu) and started gparted.
But gparted saw it correctly as a 40gig drive, thought the partition took the entire disk, and refused to let me increase its size.
Df, however, disagrees with gparted and agrees with Win98SE.
Why the heck is this happening, and how do I get the rest of the partition to be seen by everything?