Bicycle Mechanics - loose chainring bolts

I've got a 1983 Bianchi Nuovo that I converted to a fixed gear a couple of years ago. I kept the two existing chainrings on the front as I didn't see any need to remove them. I just used one of them for the chain.

I took a good spill (about 30MPH) and a couple of the chainring bolts broke and the rest loosened up quite a bit. I decided I'd buy single-speed chainring bolts and use my existing crankset/bb/etc. with the single chainring. I tightened the bolts down until there wasn't any play in them and everything was fine for a few days. But today on my ride home from work, I noticed some play in my pedals.

I pulled over and noticed that all of my chainring bolts were loose. I tightened them back up and they were just fine about two miles later when I got home.

Should I replace my crankset, bottom bracket, and all that? Should I go back to using two chainrings like what was originally on the bike (I have both chainrings and a brand new set of "normal" chainring bolts). Is there anything I can do to keep the chainring bolts from loosening?

Lastly, what are the recommended tools for tightening chainring bolts? I normally just use my Park Tools allen wrench and a screwdriver, but the screwdriver rarely spans the entire back side of the bolt. Is there a tool specifically designed for this, or do I just need a really big screwdriver?

Thanks so much!

http://www.parktool.com/products/detail.asp?cat=26&item=CNW%2D2

Tighten the bolts in a star pattern. Use some light Loctite on the threads if you're paranoid about them loosening again. Shouldn't happen anytime soon unless the bolt holes in the right crankarm are damaged.

There is a specific chain ring bolt spanner that you should be able to get at any good LBS... they're not expensive.

Keep an eye on things and if they loosen again I'd be getting the right tool and perhaps a little blue loctite if you feel you need the extra security.

I tightened the bolts down until there wasn't any play in them and everything was fine for a few days. But today on my ride home from work, I noticed some play in my pedals.
If that's literally how you tightened them, i.e., just until there was no play, that may be your problem. Chainring bolts must be torqued very tight. The recommended torque is 100-120 inch-pounds which is a lot more than you would normally apply with a regular 5 mm allen key.

Thanks for the responses, I'll look for the proper tools and try to make sure this doesn't happen again.

Use some light Loctite on the threads if you're paranoid about them loosening again.

Worst advice given this whole week.

NO chainring bolts need to be loctited. EVER. You only need to GREASE them. That is unless you like to drill out your chainring bolts everytime you want to change out the charining.

Chainring bolts that are the proper size and torqued will NOT come loose. Chainring bolts do NOT need loctite.

While you're at it, make sure you didn't install the chainring backwards AND that your c-bolts are not bottoming out.