Thanks for your reply. As I mentioned in my original post, I have indeed compiled it with the -g option (that is equivalent with the --gui, or not?). The original console window (when I double click on the exe file) is successfully suppressed; however each time the app calls a system command (netsh, etc...) a console window flashes for some seconds.
Am I having a buggy version of pp or is the system command execution the problem?