Maybe it is your geometry. I tend to shoot closer to 90 degrees when I bounce. The "normal" 45 degrees just doesn't seem right to me. And I have gotten good results with 11 foot high ceilings in my house. I use a Sigma Ef-430 Super and an N80. Nothing fancy there. I just figure that since the subjects are usually pretty close, 45 would be too steep an angle. You might play with that a bit.

Or, if you want a compromise, try an on-flash diffuser. I use a Photoflex which you blow up. Works with TTL and my AF assist light, and you get a soft light from it. Shadows are still an issue though.....