Sorry, I should have been more specific. The app works correctly when I do the File->Load, then hit run, when I do Load and Excecute, and when I've bound the .nds file types to the dualis.exe in windows and double-click on the .nds files. It works great, and I love it. It locks up, however, when I try to pass a filename directly as a command line parameter, which is why I originally suspected that my syntax was incorrect. Dualis also craps the bed when I drag a .nds file into the main Dualis window. Again, this isn't necessarily a critical error, I'd just like to simplify things.