iDVD menu problems

I created a master DVD using iDVD using one of the old static templates (lavender) and putting a jpeg over the top of it. I deleted any text that was there and everything looked perfect at time of burning however when my client played it back on her mac she saw glimpses of the lavender menu popping up where my menu shouldve been. Its not consistent and upon speaking with her it wasnt happening anymore but shes now concerned that her clients will experience the same issues.

Is this something that anyone else has experienced and if so is their a possible way to rectify and assure her that it wont happen again? I know it wont happen in an actual DVD player and it likely has something to do with her mac but i wont hear the end of it if i dont figure out a solution.

Thanks to anyone who can lend me some expertise on this!

Regan