carbonation question

i bottled a brown ale two weeks ago from today. after two weeks conditioning in the bottles, i put a few in the fridge. once cold to drink, i tried one. as i opened the bottle, it fizzed; and when poured, there was a head and bubbles rising from the bottom of the glass (bubbles rising whole time i drank the beer). however, the beer was a little flat. this brings me to my question(s):
1. should i let the beer sit and condition another week?
2. i read in several places to let the beer sit in the fridge for 48 hours before drinking--would this maybe be the answer?
i would appriciate the advice.

Personally, I'd let the beer sit another week at room temp.... after that, put a bottle or two in the fridge for the night (or longer) and try one. I'll bet you'll see better results.