CO2 regulator leaking with paintball adapter

[bmmathe]

I have a 20 oz CO2 paintball tank I want to use for kegging since my fridge is small. I bought this keg from Northern Brewer which comes with a regulator and all the necessary piping and fittings.

http://www.northernbrewer.com/shop/...-systems/5-gallon-keg-system-new-new-keg.html

I bought this adapter for my paintball tank.

http://www.homebrewstuff.com/co2-adapter-for-paintball-tank.html

The nylon washer that goes between the CO2 tank and regulator is specially designed to fit normal 5 lb tanks.

http://www.northernbrewer.com/shop/co2-nylon-washer.html

I put this in my regulator and then screwed in the paintball adapter then screwed in the paintball tank and I think there might be a small leak.

Is there a different washer for a paintball tank setup I should be using instead of the nylon washer that came with the regulator? I put a brand new o-ring on my paintball tank and lubed it up so I know that's not the issue.

Thanks for the advice

Brett