I have spacers on both my drives. I was lucky enough to have 4 of those funky orange spacers kicking around here in my pc-screw bag (with loads of hard drive screws, which I also used 4 of).

However... Even without the spacers, there is no way the spindle bulge, or any part of the underside of the drive could possibly touch the tray with the model I installed. The gap left with just the drive plainly mounted was pretty big (all things considered). I've got a Toshiba and IBM (both 30GB) installed right now.

Bruno