Sound Forge is a program that can deal with mp3s. When I say deal, I mean manipulate,edit mp3 songs. I'm sure there are others too. Well this program has a normalize option and an amplify option. By normalizing your mp3s your problem would be solved
. But do you really want to get into that much trouble? (you should first learn how to use the program, then edit all of your mp3s that you want into your cd, which is a lot of songs!
). The choice is yours.
http://www.soundforge.com/products/home.asp