I reread DBCherry's original post. I see he said opposite aileron.... I was thinking opposite rudder when I replied.

I learned to fly gliders last summer (the sit in type). We had to hold a bit of opposite aileron in during a turn. Just a bit of pressure on the stick. Otherwise, the turn tightens on it own. Something do to with the plane's spiral stability? It was a Schwiezer 2-32. It surprised me to begin with. After a while you don't think about... and just hold in what ever is required to maintain bank and keep the yaw string straight.

So I wouldn't be surprised, based on my limited experience, if a cub required a bit also.