Something strange has strated happening with my Button labels. When the app starts up, they are all offset approx 50% on thge y axis. When I roll over them for the first time, they jump up into the correct position and remain there forever after. This same problem effects my AccordionHeaders aswell (subclassing Button). The font is embedded and I have tried several different fonts, but all cause the same problem. These are just regular buttons containing no custom code. They are absolutely positioned in a Canvas.
Turns out this was being caused by what appears to be a bug. I had set quality to autohigh in the embed. Setting it to high fixed the problem.