Bicycle Mechanics - Clicking SPD pedal

I have SPD pedals, and one of them clicks as I reach the top of the pedal stroke (crank arm reaching 12 o'clock). I know which pedal it is because it doesn't click if I unclip and pedal one-legged. It clicks when I'm clipped in, and it still clicks if I unclip and just put my foot on top of the pedal.

I checked the pedal and it doesn't seem to be loose or anything. What could be making the noise?

Pedal
Cleat
Crankarm bolt

or ...

http://sheldonbrown.com/creaks.html

I had a shoe that popped when I pedalled or just walked on it. Got it replaced and fixed the pop. LOTS of possibilities for cranking noises.

Could be dry,dirty bearings. Might be time for a cleaning and re-grease.
http://www.parktool.com/repair/readhowto.asp?id=84

I had an spd pedal that was clicking, I tightened up the tension screws. That stopped the clicking. I don't know why it picked up a click on both sides, but anyway, adjusting the tension on both sides fixed it.

Could it be the BB?
I think I had this happen on my bike and my bottom bracket was broken.

Another thing that can cause a click and is seemingly unrelated to the pedals is the end of the FD shift cable. I have see it where the cable end is sticking out and gets hit every time the pedal passes it and it makes a click. This is actually pretty common.

I think I'm going to have to take off the pedal and replace it with a different one to make sure it's not a BB or crank issue.

So I took off the left pedal and put a platform on there and rode around. No clicking. I definitely think it's the left pedal. Reading through the M505 (Shimano pedal model) manual, it says that if the tension adjustment screws lose contact with the tension plate, disassembly may be required. I think this may have happened. Anybody familiar with SPD pedals specifically and the task? Should I just take the pedal to the bike shop, or could I fix this problem myself?

Did you put the spd pedals back on yet? I had this same thing happen on my shimano "campus" style pedals (spd on one side only) and when i removed the pedal to experiment like you did and put them back on the noise was gone.

Try lubing your cleats & jaw mechanism, have you tried that.

How? Just put lube on the springs? Where specifically should I put the lube?

I had a cricket that clicked outside my window. Killed it, solved the problem.

Noises can't harm you.

I took apart the clip mechanism, wiped down the springs and other parts, and applied a little chain lube. I did a short test ride and I think it might have worked. I got to pay attention to it on a longer ride.

Thanks for the help!