Carbonation Issues

What the hell, it figures I would run into problems with my carbonation right before a local homebrew competition. I was going to have about 4 beers that I wanted to enter in the Hereford and Hops Homebrew Competition coming up at the end of June BUT I had started using DME to carbonate my last 3 batches of beer, all of which have shitty CO2 going on. They just so happen to be the beers that I had been REALLY looking forward to brewing because I spent a lot of time working out the recipes, well one was a JZ recipe, but my RIS was all off the top of my head. I'm bummed out because the RIS I brewed tastes so bloody amazing aside from the fact the the carbonation isn't up to par. I have to brew this bad boy again and get the Carb right this time. The other one is a 10 gallon batch of smoked porter that I used Jamil Z's recipe for. I tastes damn good too but again, the Carbonation is just not 100%. Oh well live and learn. Not sure why I decided to change to DME in the fist place. I have had such success with Dextrose or just straight up Sucrose. Oh well, now I now. I think for any of you brewers that decide you want to go with the DME, go by a weight that you know will work rather that a volume that you are uncertain with....Or just stick with the dextrose or sucrose. That is what I have found to work the best, aside from force carbonation.

Peace out,

May all your brewing experiences be merry.
--Brian