could not apply changes. Fix broken packages first

when i try to play mp3,mp4, it doesnt play .. first it search for suitable plugins then it gives the error of could not apply changes.fix broken package first
please help me to fix dis

http://www.linuxforums.org/forum/ubu...tml#post444668

sudo dpkg --configure -a

This is not helpful ,, the problem is still there ~!!!!!!!!!!
plz give me another solution