Nikon D70 Flash problem. Single flash in TTL mode

It seems a bit unusual to me as i could not find anything similar to this online. What happens is this. I turn the camera on and manually pop the flash (in P mode) and i want to take a picture. The flash blinks but seems to at maximum power and only one time. In TTL mode it supposed to blink 2 times, one time to illuminate the area being photographed and second time while taking the picture with flash power and other exposure adjustments calculated. What happens now is that it only blinks one time very bright and the second time it doesn't blink so the actual exposure is taken without flash. Flash mode is set for TTL in the menu and its always been set for that as i dont have external flash. So, i can take a few pictures and then the flash does eventually blink 2 times like normal but right after turning on the camera it never does the 2 blink TTL shot. I have 4 battereis and they are all charged and they all are full in the display and this happens with all batteries. It also doesnt matter on the Program setting as the same problem shows in Auto also.
Thanks to all who have seen this and can provide some help.