Three Strikes and I'm Out. Why no Carb?

I find this very strange. I've done 6 batches now, and the first three i only let sit in the primary for a week and just bottled (hefeweizens and simple ales) so it wasn't that big of a deal. Only after a week they would be carbonated. Well, with the last three batches (Boot Black Porter, Blonde Ale, and Hard Cider) i've transferred to the secondary for another week after the primary to get it off the yeast, and when time came to bottle i also left the yeast trub behind. I prime with 3/4 cup of corn sugar mixed with water, and let the bottles condition in a 74 degree room. THE BEERS ARE FLAT AFTER TWO WEEKS IN THE BOTTLES. Argh, any ideas on what the deuce went wrong? And i cant beleive i have to ask this, but is it possible to poor all the beers out and somehow re-prime/re-bottle? Thanks guys, this is becoming ultra frustrating.

Well, my first batch I bottled straight from the primary and it carbed in a week. Since then I've been using a secondary and it has taken 3 weeks to get optimal carbonation.

My advice is to be patient. It should work out fine. The yeast will need just a little more time to get the work done after settling in the secondary.

Since I haven't seen your recipes or notes, the types of beers you brewed are heavier than your first 3 batches and require a much longer time to get carbonated.

Wait another 2-3 weeks. Possibly longer if you've primed with DME.

Be patient. If you can't then switch to lower gravity brews.

What they said.

Your first batches could have been bottled too early (before fermentation had completed), and because they were not transferred to a secondary they would certainly have had more yeast.
It is not unusual for carbonation to take three or four weeks, and the flavor continues to improve for several weeks after that.

-a.