Chapter Highlighting is offset when burned to Blu-ray

I have a project in Encore CS3 that I switch between DVD and Blu-ray for the
exacxt same content, menus etc.

These menus have video clips as place holders/buttons and are designed in
Photoshop CS3, that have a simple mask for the video and an outline as the
highlight. The menu has a 16:9 aspect ratio. All looks as expected when I
preview the menu in Encore CS3 for either project settings (DVD or BD).

When I burn it to DVD the menus and highlights of these menus are fine. However,
when I burn it to Blu-ray the highlight of the menus are vertically offset (not
horizontally) higher than the designed position. That is to say that the video
clips (menu buttons) show in the correct place but when I mouse over the
buttons, the highlight shows quite a ways above their expected position.