I have been there with my Curado. Did you happen to get your reel wet? The Curados or at least the older models will develop a drag problem as you described if water gets on the drag. If thats the case you can either replace the drag or take the reel apart and pull the drag out and let it dry. And remember with Shimano the drag needs to be greased. And that might be your problem. Maybe your drag simply needs to be re greased.