When I plug in the drive and boot, to my 640 with my 320 with my files and try to access it I get a BSOD with a disk.sys error. When I disconnect the drive and restart the errors go away and the system runs fine. And if I do not access my 320 with it connected it doesn't really crash often but when I load up SpeedFan which tries to detect SMART status of the drive it crashes. And If I try to write to the disk it crashes as well.
I am just thinking that the drive is on its last legs and time for a replacement since this drive is about 4-5yrs old anyways.