Yep, your problem is not the hub, freehub or cassette at all. It is entirely a problem with the frame. Your seatstays and chainstays are linear / inline with the dropouts - i.e., they do not flare out before joining the dropouts - nor are they scalloped along the insides. These are old style entry level dropouts common with mass produced entry level road bikes from the eighties and early nineties. They'll work fine with 7sp, 8sp and possibly 9sp...but 10spd is really pushing it - especially with Campagnolo as they take a little more liberty with using up drive side axle end space for the cog set.
Adding 1mm washers on each side MIGHT help...just make sure you have at least 3-4mm of axle in each droput when done.
=8-)
Good Luck!
=8-)