I'll explain exactly what is happening for me when I try to do a custom capture. I want to capture things like Youtube video's or other things that are only a part of the whole webpage.
This is what it looks like when I select custom and then click the drag option and drag the window around what I want to capture.
This is what it looks like when I stop the capture and it goes into VSP, notice how it is way off
Hope this helps you guys understand what is happening to me when I try to capture just a part of a webpage, it isn't doing what it should.???