TheBillyBobJr,
Sorry about the delay in responding. I spoke with our R&D group about the grey lines that you are seeing and they let me know they are result of the windowed designed of the control. The main reason you are seeing the lines in your particular situation is that you've changed your Graph Frame Color. You should be able to keep your black background and modify your frame color to alter the look of these grey lines. I apologize that there isn't a better answer for you but these lines are a result of the design. Let me know if you have additional questions. Have a good one.
Regards,
Adam B.
Applications Engineer
National Instruments