Please post a picture or video. I love Australian saddles, but they do not distribute weight over as large an area as a western saddle. If your weight is to the rear of the saddle, then your riding could cause the pinned ears.
Do you know how to ride in 2 point? If so, try doing that. Or see if it happens with another rider.
BTW - my favorite pad for my saddle is a standard, cheap, folded 30 x 60 thin western one: