Hm, that code should work, and if you're using the EJEJC_BEACON parameter, you won't need to use any other AdWords tracking code, as we'll hit that conversion URL whenever we process an order for you.
I examined the code on your bunkbedking site and noticed that the beacon URL your page specifies has '& amp;' in places where it should have just '&', so that might be a problem. BTW, I also noticed your bedzking site does not use the cart customization code shown above at all.