Webcam avicap32dll Workaround ? when capture window minimized

Does anyone have a suggestion, when capturing Webcam video to a picture box window automatically, if picture box window is overlayed by another window, or minimized, the clipboard is not refreshed?

I presume that the hardware binding capture window to picture box must be addressable in memory, what is really weird: if only a few lines of pixels are available on screen, I can capture all webcam window, but as soon as all pixes are overlayed, no more capture to clipboard and always saves same image...

MAJOR limitation, any ideas, workarounds appreciated...