Help! My Belgian Trippel has fallen and it can't get up!

Hello all.
I've been brewing kit IPAs for about a year with no problems. All extract recipies, pretty basic stuff, and very tasty.
The latest beer batch was an experiment with my brewing buddy. He picked up out a kit for a Belgian Trippel from More Beer in Concord, CA. We brewed it up, fermented 5 weeks, bottled two weeks ago, and it sucks.
The sweet flavor is there, but there is no carbination, no .... beerness.
Sorry for being so vague, but its tough to say that it doesn't taste horrible, but it sure doesn't taste like beer.
Here's the play by play...
7 gallon kettle with 6 gallons of tap water.
6lbs German Pilsner Extract
3lbs Light DME
1lb Clear Candi Sugar
No steeping grains.
1 oz Vanguard Hops
1 oz Sterling Hops
I vial White Labs Trappist Yeast
Fermented 5 weeks in glass carboy in dark closet that stayed around 70 degrees
Bottled into standard brown 22s
Used 4oz of standard corn sugar with 2 cups boiled water for carbination.

WHAT THE FRAK WENT WRONG?

Have we simply not waited long enough for the carbination to take hold?
Should there have been more yeast?

Any suggestions welcome...

RDWHAHB!

Just wait longer, higher alcohol beers (like this one) can take much longer to carbonate. I had a beer that took 6 months to carbonate!

I don't think any beer can carbonate in only two weeks. I find that if I open several at four weeks, the results are inconsistent. Some will be more carbed than others. It's better at five weeks, and fully consistent and fully carbed at six. Now I always just wait six weeks after bottling before I start consuming, and I wait even longer (3 to 4 months) for big beers. In the latter case that's not because of carbonation, but because big beers need more time to mellow.

You didn't post gravities. I'm currently brewing(battling) a Belgian trippel 12G that stuck during fermentation. As of monday 2G finished @1.020 and tasted very nice even flat and green. This one sat on a double yeast cake. The other was at 1.030 today(still slowly fermenting). It still didn't taste right. Big beers need very large starters. When I kill the keg tonight the 2G will go in it and the yeast cake will go to the 10G. My suggestions are to take gravities so you know where you were, are, and want to be. Use a huge starter, give it more time, start fermentation at low temps then warm it up to help the yeasties and RDWHAHB.

+1 to what the others have said. This one will take some more time.
I have a Brewers Best Tripel that's now been bottled 5 weeks. I sampled 1 last night to check carbonation as I was a little worried about this one as the FG was a little high. Carbonation is just fine and the beer now has a fairly noticeable alcohol taste. I think this one will get stashed away and I'll come back to it in a couple months. It should be good stuff by then.