ORIGINAL: Tall Paul
Sounds like the typical tip stall caused by letting the airspeed get too low, and putting in an aileron command.
The downgoing aileron stalls the wing section ahead of it.
This creates a imbalance in lift as the other side is still lifting, and the plane rolls opposite the input command.
Happens to everyone when the speed isn't kept up..
Okay, that makes sense. Thanks very much for the info. I had never heard of "aileron reversal" before.