#2. "RE: D90 Popup Flash" In response to Reply # 0
Are you saying that when you press the flash button the flash doesn't pop up, or the flash doesn't pop up automatically? The flash will only pop up automatically when the camera is in Auto exposure mode or some of the other pictogram modes. When the camera is in P, S, A, or M exposure modes, the flash button must be pressed for the flash to pop up. Good Luck and Enjoy your Nikons!
#3. "RE: D90 Popup Flash" In response to Reply # 0
Widnes, Cheshire, GB
My wifes D3000 had a problem of the built-in flash not poping up, on one of the occasions when it did i squirted a small amount of DW40 onto the two little springs that you can see on each side of the flash as you look into it from the front. The flash has never failed to popup since. May not fix your problem but good luck.