Bicycle Mechanics - Crank Ring bolts - different size or washer or what?

This morning I pulled my Shimano 105 crank off my road bike to try to tighten the crank ring bolts. They are max tight as far as threads to apparently, but there is still play in the rings. :( Loosescrews.com is down and I'm going to be running to the LBS in an hour or two - but wanted to ask - what are my (best and/or cheapest) options on getting this problem solved?

Thats weird!? Are the threads stripped or crossed? The bolts or "nut" can crack if they are alloy..

All of them are about the same amount "loose" and what I'm suspecting is that the Stronglight (Nashbar) 52t ring is slightly skinnier at the attachment points than the correct Shimano ring. Thus causing the bolts to be loose even though they are threaded together as much as they are able to be. That or when I bought the crank the bolts that sydney sent me were originally for a different crank that specifiy slightly longer bolts perhaps. In any case, I figure a small washer either on the front or back side is likely the best answer to the problem. Any other opinions before I get cleaned up and head out?

Somtimes there are very thin spacer washers between the inner ring and the crank arm tabs. Could they be on the floor where you disassembled it?

Crank bolts are usually 8mm. You can find 8mm washers at any home center or Hardware store as an expedient.

Svr is correct that some cranks do have spacer washers as standard equipment but the Shimano 105, IIRC, doesn't

If threading into the spyder, use shorter bolts.
If threading into nuts, and the nut\collars are wider than the ring\mount =spacers to the front of the bolt (outside the ring) OR grind a mm or two off the nut ends?
i've not seen short nuts...though someone makes them I bet.

.......?

Went through this with a friend in the fall with a chainring swap - easily fixed with washers.
Spacing washers were $1 each (!) at the LBS or pennies at the hardware store or bike co-op.

I just went through this while converting a triple to a single for a single speed. The bolts weren't the problem, it was the nuts. I ended up grinding them down a bit.

Yeah, I took the expensive way out - new bolts at the LBS. I'll mark this one up to "supporting my local bike shop."