My new IBM 34gb harddisk is identified correctly at boot time as 66305 cylinder (16 heads, 63 sectors). However, when I start up fdisk it shows me 769 cylinders, which is equal to the lowest 16 bits of 66305. "sfdisk -g" also shows the disk as 769-cylinder. However, cfdisk correctly displays the number of cylinders (after creating a empty partition table with fdisk). I guess if I had used some other DOS or Windows based utility (urgh) then that util might have wrapped the whole disk into (4160,255,63) or whatever and this problem wouldn't have occured since I've noticed that linux detects the actual used parameters (if it can) from the partition table.
Michael, is this a kernel bug as Matt suggested?
Red Hat Linux 6.1 had an fdisk that couldn't cope with such large disks. I'd recommend upgrading the fdisk to at least the 7.0 version.