Re: Mp3 format woes.
Mp3 should always be rendered to 192Kb/S. That's where I get my best results. I would happily say that 98% of people couldn't tell the difference between high-quality Mp3 and PCM. If the file needs to be smaller than 192 allows, use the variable bit-rate option. Works wonders.
Either that or try the .ogg format. It's a little more transparent than Mp3.