Hi, fairly new to this and I need a bit of help. I have a Jamma with a J-Pac and all seems OK when I connect my PC up to it. I have tried 2 different GFX cards and on some games the screen jumps and these lines appear. Very strange, on the menu the are horizontal lines which go over the screen. I am using Advancemame and Advancemenu, some games appear fine but others jump like crazy, ie, R-type is fine but R-type leo jumps. Any ideas, I am pulling my hair out!!!