I suspect that you are not getting everything off that drive. If this were mine (and it takes some time), I would use something like Dban to wipe that baby clean, because formatting does not entirely clean the drive. If interested in info:
Dban Complete Disk Eraser
Please note: Be sure you have all disks unhooked that you do not want formatted and cleaned, because this program while great has the capability to erase multiple disks at one time if hooked to the computer. When you have finished, then give it a try with the install and see if all the "bad" boggies are gone.