[cinemaker] “he highlights look great in Photoshop…”
Photoshop isn’t the ideal environment to judge your button highlights, unless you understand how they work on DVD-Video.
Subpictures are 2 bit graphics. That means one color, and one opacity value. No gradients, drop shadows, or other ‘soft’ effects will come through correctly. No anti-aliasing, just one color value, and one opacity value.
What’s in your subpicture layer?