OK, a though one:
This is my  settting: TV (50Hz)
                                 Scart (with hacked cable from http:  //www.jayma.org/mamescart) 
                                 ArcadeVGA
                                 Act-Labs USB LightGuns.
Symptoms: - When I turn on calibration, the calibration screen doesn?t appear.
-   The trigger doesn?t do anything.
I haven?t been able to make it work. Does anyone has had any success with it ?
Thanks.  
