Umm.... why not just light a candle and use that for your light, it will not be much worse than what you are using, and the quality of light will be better also.
Kidding aside, you are WAY WAY underpowered on your lighting. Also, for what reason are you using those settings? 1/100 at F4.0? What lens are you using? What subjects are you shooting?
To use your current setup with quality results, you are going to have to get the camera on a tripod, set your aperture to max opening, with ISO no higher than 400. As said in the other answer, use A priority and let the camera meter off your subject. You will undoubtedly have a shutter speed of a second or two if not longer. You will need to use mirror lock up on the camera and a remote shutter release or the self timer to fire the shutter to avoid blur due to mirror slap and camera shake.
It sounds like you are trying to do something with nothing approaching the correct lighting or camera technique.
Invest in a quality studio light and life will be much better for you.
http://www.alienbees.com
steve