hey,all... it's a long story.. I try to install bsd subsystem to my ipod..finally bsd was useful and i try to uninstall it..but on installer there was only reinstall button.. so i try to manually uninstall it using winscp. i delete some files on media_sys/var|usr|sbin and nothing happened (foolish i know!!) then i switch ipod to restore mode and finally bsd subsystem remove from ipod.. now when i restart my ipod and use any theme from summerboard at the welcome sreen the wallpaper is the default black background....and after access music videos etc.. is going to normal theme.. it's a bug, nothing ..or something stupid by changing system files...??