Thank you for your help. Actually I was using lines to make the grid. The other option you mentioned is bit to advanced for me
But luckily I found out what caused my problem. If you set the display mode to for instance 640 x 480 and then maximize the window, the window is stretched out. That will make some lines become thick and others thin. When the display mode is bigger then the actual screen size, the window will shrink its contents. So lines will disappear.
What I hope to achieve now, is that my DB window will overlap the Windows taskbar. So I can just pick my screens resolution and fully use it for my program. But I haven't found a command that will let me do that.
