What makes you think it's dying? Is it making sounds, giving errors in Disk Utility, or corrupting files? If it's just not coming up in the finder, it could be the same bug blocking my flash drive, or it could just be a bad power supply in the disk enclosure.i think i have a dieing drive...time to hook it up to Spin Rite and see if i can fix it for now..
Most drives last until good time, but occasionally bad time comes first.