Boot stalls/repeats - verbose boot reveals stall on Bluetooth

Question

I have a problem with my MacBook 2 GHz running 10.5.1 - the boot up stalls and keeps repeating itself until eventually it will continue and boot up.
It gets to the gray screen with the circle graphic...sticks there for about 2 minutes and then shuts down and starts over. It usually does this between 5 and 10 times before it will continue and finish the boot.
Here's what I've done to try and solve the problem:
1) Reset PRAM - no change
2) Reset system controller - no change
3) Remove battery and put back in - no change
When I run a verbose boot (command + V) the boot stalls on a Bluetooth controller entry. I can't find any reference to that.
This started happening after I ran system updates a couple of weeks ago. The unit functions correctly in all other areas. Once booted up you can put it to sleep and resume with no problems.
Ideas?

Answer 1

Your disk is dirty, clean it with a bit of rubbing alcohol and a soft clean cloth to polish.
Hold c and try booting from the disk now,
if it doesn't work, order a replacement, either a 10.6.3 retail (no free iLife, comes faster) or machine specific 10.6 disks (for machines that originally came with 10.6.4 or later you must use these)
When you install, use Disk Utility to Erase with Security Option > Zero the new drive, it's better for it that you do, maps off failing sectors ahead of time.
last resort to install is making a 10.6 boot USB on another Mac, in case the optical drive is bad
http://www.maciverse.com/install-os-x-snow-leopard-from-usb-flash-drive.html