Can't get a screenshot from a capture device

[jumpjack]

I have an old MuchTV USB 2.0 capture device; I bought i in bundle with a capture SW.
I noticed that using a screen-capture program I cannot capture what I am seeing in program screen: I get instead a black box, or a purple box! :confused:
Does it exist a method to override this "feature", which sounds like a copy protection?!? :confused:

[neuron2]

You can't capture graphics overlay contents that way. If possible, turn off the overlay in the MuchTV software.