Choppy playback

Now that I've finally gotten mod_mp3 to stream files, I'm running into a 
problem that I suspect is not correctable. I'm getting choppy playback. 
I'm assuming that this is a bandwidth problem and there's nothing I can 
do about it. Anyway, I'm on a cable connection, but I believe my 
provider (comcast.net) is capping upload speeds (dslreports' speed test 
shows me at 1200/100 kbps download/upload).
Is there anything that can be done (other than changing providers)?

Thanks,
Tim