Thank you. As always you are the MAN. You know what you're talking about.
I got the drive from my son-in-law who had first used it in a drobo setup, but it quit working for him. When I put it in my box and it worked just fine, I figured everything was alright.
So, I should:
1. backup the information on the drive.
2. use gparted to reformat the drive as ext4.
3. restore the information from backup.
4. try to reinstall 2010.
If you are strictly a GUI type guy, you could try that. I would use dd to wipe the first two sectors of the drive, then use fdisk to partition, and mkfs to do the ext4 format. Different strokes, and all that. If the drive really has the GUID partition table, there could still be the end of the drive stuff present, so fdisk might spot that, and still complain, in which case I'd wipe the entire drive and start from scratch with the DOS partition table. The reason I wouldn't try that first is simply the time it takes to wipe a drive that size. Why wipe a whole drive, if a couple of sectors will suffice?

Backing up the data is an obvious given.

Whatever partitioning tool you choose to use, I'd still use dd to wipe past the first two sectors.
[root@localhost ~]# dd if=/dev/zero of=/dev/sdb bs=512 count=300