Hello, I had a similar problem with my 120 GB seagate disc which has 4 kb bad sectors.
I could not resize it with gparted-livecd-0.3.3-0 because of the bad sectors. I tried to run some chkdsk /f /r like suggested without luck. The solution was to use qtparted v0.4.5-cvs running from KNOPPIX 5.1.1 live CD. Qtparted ignored the bad sector problem and resized the disc. Running the same version of qtparted from kubuntu 2.6.15.27-386, generates an error when trying to resize.
I have also heard that you can use ntfs-resize with bad sector option selected.
Hope some of this can be used by others
Good luck.
Grzegorz Nowak, webdrive.dk admin.