If the application is truly "hanging", that is, execution is stuck in an infinitely recurring loop, my first suspicion would be a circular reference somewhere in the data. If the app is not actually hanging but suffering from extremely poor performance, it is possible there is a bug in the control. You did not mention the number of columns at which the control becomes unuseable, but generally speaking the more detail the better...you might want to either post a sample application here or log an incident with Developer Support and include a sample there. It is difficult/impossible to speculate about the problem without seeing the code.