Rear speaker input wont play internet sounds

Hello,


I'm trying to play the sound from the internet through the rear sound hole (the blue one) .
if i want to play any thing from the hard disk it works well .
but it don't play the sounds from the internet .

the driver software is realtek HD and i set the blue hole (input whatever...) to be rear speaker .
i have windows 7 now but i had the same problem when i had xp
so i will be very happy if someone could help me .
by the way have a pc with inetl dg33bf motherboard and the audio driver is built in .

i don't want to use it as a rear speaker just for the headphone , i dont know if that can help .