Handling missing pieces when running GUNITE in an automated environment

I am uniting a split file using gunite.exe and command line parameters in an automated environment (i.e. no operator or human present). I have specified the -u switch and all works well, but if a piece is missing (this happens if there is a delay in the network that is transmitting the pieces) I expected to get a return code of 2. Instead a window is displayed with an error message and operator input is required. How do I supress this window, fully automate the unite and log the error, i.e. get a return code of 2?

Added your bug report to the TODO list. It looks like a message box is displayed while it shouldn’t.