OK, this is by far the strangest bug I’ve yet to find in Flex.
Sometimes when I loaded my application, my tooltips and my popups refused to render any content. They were just empty. (See the images below, both the good and the bad). And when I went to debug the application, the properties were still there as they should be, just without the text being rendered.
The closest thing I could find on this out there, were people who were getting a runtime error in Flex 2 when their Modules had problems with the singleton classes such as PopUpManager and DragManager. But then I did some more research and I realised [finally] the problem was that my embedded fonts weren’t always rendering after I loaded in a module.
So when I removed the embedded fonts, and bobs-your-uncle.
Still, I’d love to know if anybody else has come into this and ways around it…