I, too, can reproduce this ("Access violation at address 0047C071 in Module 'PINGPLOTTER.EXE': Read of address FFFFFFFF.). It is not always predictable, but occurs most easily if you pick an unreachable host. Once the error occurs, clicking anywhere in the dialog (including the close button in the top right corner), or clicking ouside the dialog so that another application comes to the foreground, increments the Samples to include count, and generates the error. To close the dialog, you have to right click on the application in the task bar and select Close.<br><br>