I have been busy trying to convert a menu structure that I created within tab structure that are all based on .png icons (200+) since I had a complete blow out of almost 3x file size on conversion. I have deleted the icons and changed the field that sat on top of these to a native gradient fills, with a simple conditional format that value is empty use transparent fill. Nice and simple but after setting this up on all the field, I was not working in all cases, until I went back into conditional formatting and clicked on fill transparency again. (like the old issues of copying a variable from one layout to another in 11) but this was all set-up in the same layout only different tabs.
I have copied the field/format into a new file and added a single field for it to reference attached same issue once you enter conditional formatting and reapply transparency to the fill it now works. (This is in the new copy of FM12A not the prerelease that was deleted OS 10.7.3)