Quote Originally Posted by foamrotreturns
try using the utillity "dban" on the disc. It's a hard disk wiper utility. This will erase the ENTIRE hard drive using a multipass technique. It's normally used for erasing sensitive data, but the hdd becomes truly blank after this. No MBR, no partition table, nothin but zeroes. So back up any data you want to keep, because it WILL be gone after using this utility. If you still have the same problem, you're probably looking at a hardware error.
Another thing to look at is a diagnostics floppy from your HDD manufacturer. Western Digital has Data Lifeguard Tools, and each manufacturer has their own. This technique got me out of a bind once. I had written a really nasty bad sector to the hard disk and it would not even load in any 3rd party application, no matter how low-level.
The dd if=/dev/zero of=/dev/hda count=1K should erase the partition table, Master boot record, boot sector, ... and is much faster than erase the hole disk. Be careful, this is a very powerful but dangerous command !
Cheers, Gilles