Portable unrecognized

my comp recognizes the device, but samsung media 5 does not, i have to yp-s2 1 gig, it works fine, i can charge it and music plays great, but i cant put ne more songs on it now, plus i try to burn a cd with the software for media studios 5 and it will burn for a while but then it stops and sumting happens, it will put only 2 songs on the cd if that..i have uninstalled and then reinstalled and nuthin,, i dont know what the prob is..