need help: media icon of edge ds doesn't work

i've been using my edge flashcart for quite a long time now but upto now i don't know how to make the media button to work. i just keep on ignoring it because i can access the moonshell on the games icon, but right now i really want to make it work. i reformatted my micro sd but still no luck. any detailed help will be much appreciated. Thanks a lot!!!

Try reinstalling the firmware. http://www.linfoxdomain.com/ds/

i got it fixed, but now i have a new problem :( lock thread pls thanks!