How to extract the most flavor out of vanilla beans? Today I made creme brulee, which I'm not very familiar with but have done once or twice.

The consistancy was fine, aswell as the caramelized sugar, but it had a very low taste of vanilla, even though I used 4x the amount specified in the recipe. (I used 2 whole vanilla beans for 2 cups).

I cut, scraped and put everything in cream/sugar, heated to about 80-90c (almost a boil), mixed with the yellow of the egg(yolk?) and cooked it in a pan half-full of water.

Is there anything I can do to facilitate more vanilla flavor? Is it somehow volatile and doesn't survive.. cooking? Maybe I should have boiled the cream with the vanilla? Make extract using high-strength alcohol first? Buy better vanilla?
Getting the Vanilla from the bean to the taste bud takes time. While many will advocate the use of fresh vanilla beans (as you have tried), I have always preferred the flavor that is granted from a good vanilla extract. In my opinion it is stronger and better distributed throughout the dish. Whether you buy or make your own extract I think you will get a more consistent and rich flavor that way.

(note: thanks to @rfusca for providing the extract link in a previous question)