user drawn controls controlling before forms background

i have several user drawn controls form, unfortunately form shown user drawn controls arrangement before forms credentials rather tide forms background.

the onpaint eventuality unequivocally simple, onbackgroundpaint eventuality empty...

like this:

    stable overrule vacant onpaint(painteventargs pe)
    {
        pe.graphics.drawimageunscaled(_bmpimage, 0, 0);            
    }

    stable overrule vacant onpaintbackground(painteventargs pevent)
    {
        //leave empty...
    }

how i tide credentials clarity shown, rather credentials before form?