I must have pressed a wrong button somewhere...

Had a completed DVD with three thumbnail (image/text) buttons, and a text only button laid over an MPEG moving background. All was well.

Did something (have no idea what).

Now I see the same screen working perfectly in DVDA preview mode, but when I burn the disc, all that shows on the screen is the background MPEG.
All thumbnail images and text, plus title text, are gone in the burned DVD.
Tried raising each element to "top of page", but still no help.
All links still work, if you know where to point or simply move cursor...
but disc is useless without screen navigation showing.

Any ideas, before I have to rebuild entire DVD?