I'm using it as a standalone copier at present. It's not given the same problem under Windows 7 but I've not done very much with, printer was only purchased last Monday
There no alternative feed on the WF-2520. Copy options are about paper size, plains/vs photo, quality & density.
A4, plain paper, std quality, std density, only the first 2 pertain to the mechanical handling required.
I set it to a smaller size, the sheet fed ok and it printed a reduced size image, not surprisingly. I set it back to A4 and 1 sheet fed ok. It is intermittent (as many problems are) and it mainly happens on sheets that I am printing on the second side.
I'll have to continue to monitor it and see how it goes. Is there a paper sensor that could be faulty??