I am a 32F, so I know your pain in finding a decent sports bra. I can highly recommend this one from Anita - it's their 5527 sports bra. It's a little pricey (about US$60) but totally worth it. It's fantastic for aikido and jogging.
It's very comfortable, doesn't dig in or poke and has washed and worn very well, considering the harsh treatment it gets from me hitting the mats. Here is a link to it on an Australian site so you can see it in the white - it's also got a mesh back which is really good.
Thanks for the link.
I think what I'm learning here is if I want a good sports supporter, I'm going have to invest and stop being so damn cheap!