Just a note to zonealarm and other Firewalls that are throwing prompts to the user: When your game runs in Fullscreen, it's a random game if this popup prompt is visible at all, or if it's drawn to the backbuffer, because when you use FLIP, Blitz's Doublebuffer system will flip, but Windows will always draw to buffer 1. For a simple workaround see code archives: "coordinated Flip", in "Misc" AFAIR.