Only flap changes I know of are an improved anticorrosion process and changing the fairings from plastic to metal but that was back around 2003. I don't know of any flap failures although I admit I think the ones on the Columbia are prettier albeit probably a lot more expensive. There were some flap relay failures but that seems to have disappeared years ago even for older planes. There was one aileron hinge failure but that was due to servicing where the nut wasn't safetied down.