Looks like your flash is washing the pictures out. And direct flash will do that. You need something to diffuse/redicrect the light. Get yourself a notecard and make a ghetto-fab flash bounce to direct some of that light up. There are a bunch of DIYs on how to make a flash bounce, and is a handy method to use in a pinch. You could also forgo that and just get a speedlight that you can aim any which-way.
For reference (both photos taken with no ambient lighting):
Direct flash:
Bounce flash:
The difference is pretty easy to see. With a direct flash, you get very sharp shadows and blow-outs which can ruin your composition, even with a lot of post work. With a bounce flash (or even a good diffuser) you redirect the light all over the place (hence the name) so that you get a more "natural" looking light that completely envelopes your subject and softens shadows as well. You're on the right track with your backdrops, now you just need to get your lighting up to speed. Oh, and use an imagehost that doesn't strip your exif data :laugh: