The other evening, without thinking, I went home leaving a file open in FileMaker. Normally this is not a bad thing, but this was the night when Window updates are pushed out. It rebooted my computer. I opened the file to a mess of fonts. Data was good. In layout mode I selected all, and changed the font from Z@RE713.tmp to Arial. It only affected layouts that were using the Bamboo theme.
Where tabs were used, the background tabs are still displaying the bad font. When Active their display correctly. In layout mode clicking on the item and they show the correct font.