I have a base class, C, and two derived classes, C1 and C2. I'm using a [self className] in a conditional to see if the object is C1 or C2 and take the appropriate action. This works fine in the simulator but, when I compile for the device, I get a warning about how "C may not respond to className" and, when I run the app on the device, it crashes on that line of code. Does anyone know if I should do something different on the device for this sort of code? Thanks!