HY! I have some problem with synchronisation with a background sprite that I am scrolling (with an overwritten Domove procedure). DoWaitVBlank option works, but I''ve already some little jumps. So I tried it with IDirectDraw.waitforverticablank, I had the same result... idem with the assembler code where I look for the third bite of the graphic card. So has someone an idea, from where my problem should come, and how to solve it? Kathy