Some carbonated and some didn't?

My first batch has been in the bottle for a little over 3 weeks now. The first one i opened tasted very good and i was impressed So i went for another beer and it wasnt carbonated After popping a couple more it seems there are more that havent carbonated. Should i just try and warm them up? Or did something else go wrong? It was a normal pale ale that finished where it was supposed to and i added corn sugar when bottling.

did you prime the whole batch or bottle by bottle?

I did a batch a little while ago that I had the same sort of problem. A few bottles were carbonated perfectly but for the most part the beer was flat. I added the sugar to the entire batch and not bottle to bottle so I was frustrated. what I realized I had done was just not cap the bottles firmly enough so it wasnt an airtight seal. Now every time I cap I press down on the capper as hard as I can and I havent had a problem since

Thats a possibility Pivot. My girl friend capped so it would be nice to pass the blame along. haha I have shook a few and they all bubble in the bottle. If they werent air tight would they bubble like that w/o beer coming out?
But yeah i primed the the bottling bucket. I belive i added the sugar and water and then siphoned on top.

Next time cap them yourself.
Also, I like to dissolve the corn sugar in a cup of boiling water (just put in microwave) then let cool to room temp and mix (stir gently) with the wort in the priming bucket. If you simply drop the corn sugar in and don't take the time to mix it properly, then it can settle on the bottom of the priming bucket. If you immidiately siphon from the top of the bucket, your first set of bottles probably have no sugar.