doesn't sound too much like lateral weight is that far off you probably would have noticed a lot of trim input intially. try fly the plane several mistakes high,slow the plane down enough to where you gradually input all the elevator till it stalls if everythings ok it should stall nose first with out much wing drop from either side. from what I understand the slower you fly the plane the more input from the elevator is required to stall the wing.

http://www.rcaerobats.net/trim_chart.htm

try this website also for some info,I'm still learning all these little trade secrets myself.