I just finished a long project that seemed fine until I watched it on TV. All the menus I have are pictures, and they flicker. But not when I preview.
The pictures are all jpeg and of a good high resolution. They are thumbnail size.
Preview on a PC is quite different from a TV where Interlace flicker can be seen.
Either make sure that the pictire is deinterlaced in your Paint program before using it, or, better still, DVDA3 has a Reduce Interlace Flicker feature for Menus, which helps background pics AND text added for buttons etc.