Digital is like shooting transparency film. You have to expose for the highlights.

Does your camera overexpose if you stop using the flash?

It is possible that the flash mode you are using locks the shutter to a speed low enough that it can synchronize. You may need to lower the ISO setting, stop down to a smaller aperture or not use flash outdoors. Synchro-sunlight flash can be a very effective and attractive way of opening up detail in shadows, but it requires a substantial level of understanding. It would be a good idea to review both the camera and flash manuals on the subject.

Thank you both for the responses. I usually shoot these with a ISO of 100 as far as the aperature I have tried to stop it down a stop or two to try to compensate for using the flash to fill in shadows. All other colors and Exposure are great except the whites (wich are blown)as far as the flash I use a diffuser to soften the light.
Hope this helps explain a bit more what I'm doing.

The flash is outputting enough power to adjust for the stop down in the aperture. I suggest that you try using the FLASH exposure compensation dial to turn down the FLAS POWER. Probably by 2 stops.

Thanks I'll give that a try. Oh can I do that even though I'm on TTL or would I have to go manual on it? I've tried to play a bit with manual and it gives a hard flash on manual. I think the origional setting is 1:1 What would you suggest I take it to?