Very weird, I just had the same problem. I partitioned/formatted the drive in WinXP and rebooted into Linux. When I mounted, I could see the files that I had on the disk but could not delete them or write at all. I tried changing permissions to 777 before mounting and that didn't help either. Luckily, I didn't need anything on the disk, so I partitioned/formatted in Linux and it works fine now. Anyone know what might have caused this?