built-in speaker problem? (3rd gen ipod clone)

[starthepirate]

hi!

i just bought an iPod Nano clone from Amazon, and it's really nice for what I paid, but there's one problem: whenever i use play music and video with my headphones, the built-in speaker doesn't turn off. (and it doesn't even come on while listening to the radio...)

it's a "3rd generation", real 4 GB, like this one: http://www.mympxplayer.org/album_sho...php?pic_id=578 , except the playing screen set up is a little different, as in mine has little headphones at the top next to where it shows which function it's doing (repeat, normal play, etc), which makes me believe that it CAN be switched off...

does anyone know a way to turn it off? i really like the speaker but am willing to disable it if it's the only way. i've looked everywhere and can't find anything about it.

also, it doesn't have screws, so if i have to take it apart... how can i easily and without totally murdering it?

thank you so very much for your time! =D