--- UPDATE --- problem solved.....  but so far my conclusion goes that PBX (in my case) has a different monitor numbering then Windows has. When doing it right : telling PBX what monitor is what according to the Windows monitor assignment it does not work. By try/error I could find the monitor numbers PBX is working perfectly although there is no relation with the monitor numbering in W7 (and yes,  from left to right playfield, BG, topper) See this config but although strange