A few flat bottles?

After 3 weeks in the primary and 3 in the bottles, I put a 22oz and a 12oz bottle of my second batch ever- an extract-recipe Wit- in the fridge. Cracked em open a couple days later, and was happy as could be with the results. Wonderful taste, rich head, clean finish, etc etc etc.

Threw another 6 pack of 12's and a few 22's in the fridge. Me and my girl killed the 6 pack on Friday night, completely full of ourselves because of how good it came out.

Then we cracked a couple of the 22's last night- FLAT! Almost no head at all, and the flavor was of course affected. Very disappointing.

Has anyone ever had this problem before, where some of the bottles will end up flat? What could have caused this? and how do I prevent it?

Thanks for any advice.

It takes a little longer for the larger size bottles to carb and condition....I wrote a long post explaining this awhile ago, but the mechanics of why don't really matter. Just pull the ones out of the fridge, when they warm up a bit, roll them baclk and forth on a table to re-suspend the yeast...and put them back in your warm spot. Check on them in a week, then maybe even another one.

I bottle some beers in pints and 22's and they always take longer than my 12's of the same batch.

Think about it, the yeasties have to eat more in the larger bottles so it takes them longer to go from top to bottom, and "fart" co2.

Perhaps a little more information on the bottleng process you used would help?

How did you sanatise the bottles?
How did you prime the bottles/batch?
Was it only the 22's that didn't carbonate?

Hope we can help...
EDIT: Wow Revvy, beat me again... And with actual helpfulness!!!

Could the cap just not have been crimped on tight? Had 2 cases of 12 ouncers in my batch of cream ale, all perfect except one. Had to be the cap.