bug with secondary monitor

[online]

hi.
i've been looking for solution on the forum search but haven't found a solution.
here is a problem.
i use Windows XP SP2 without its native explorer.exe, instead i use my own system but it doesn't work with graphical subsystem directly, only through the windows forms. but it doesn't matter.
after the loading of Windows i try to start bsplayer's playlist on the secondary monitor and there is only black area on the monitor. no videos but when player jumps to next playlist item some border arises.
then i execute explorer.exe and bsplayer works properly. one more solution is to replace the window of bsplayer to primary monitor and then back to sec. monitor (picture also arises).
what could it be concerned with?