Custom Buttons invisible on DVD players, but not computers

I've been a long time reader here, but I've finally found something that has me stumped and I haven't seen anyone with a similar problem; so here goes...

I'm creating a demo reel DVD with some custom menus and transitions I've made in After Effects. I put it all together in Encore, and the preview looked great: my simple rectangular buttons were appearing right where they should on my motion menu. Test DVD's played on my Macbook looked great, too. However, when I pop it into a few DVD players, the buttons are invisible. The buttons work just fine; I can navigate my way around the DVD, but only because I designed it and know where to go. No buttons are visible. Any help?

I've tried bumping up the bitrate, and turning down the burn speed, but nothing seems to fix it... I'm sort of new to Encore, so I'm not sure if there is just a simple setting I left unchecked or if there is a more nefarious problem... Any help would be appreciated!

-brian davis