would help if you explained your problem a little better. "just can`t play mp3s properly!!!" doesn't tell us much. Is the sound quality low and grainy? Skipping and jittering?
If .mp3s play but quality is low then run sys:prefs/ahi (AHI prefs prog) and try increasing the card's frequency setting. default is usually quite low, so just whack it up fully (around 48KHz, i think). see if that helps.
if the quality is ok but you have pauses and skips try increasing the buffer settings in AmigaAMP.
