a problem about mounting the cdrom on knoppix 5.0 live hd

i had a problem when i put my audio cd into the cdrom driver. i could't see and listen the songs in cd. it says device could't mount and

mount:the type of file is wrong and choice is wrong a superblock over /dev/cdrom
there is also a problem i want to ask i installed knoppix 5.0 last day firstly as a multiuser and i could see and listen audio cd but i coul't see any data. i installed knoppix 5.0 than but as a system uer (recomended) now i can not see audio cd and mount it but i can see data cd at the same time there are two icons on desktop "cdrom" and "cdrom1"

thanks everybody who doesn't write :) now everythink is ok !