Flex 4 Disappearing Labels with Embedded Fonts and Charts

I'm using an embedded font in Flex 4, which on its own seems to work pe开发者_StackOverflow中文版rfectly. I then added some charts and specified the -fteInMXComponents compiler option to get the embedded font in the charts. When I did this, the axis values in the charts disappeared.

I'm using FB 4, and I then tried upgrading the SDK (only) to 4.5. This fixed the disappearing axis values problem and all seemed to be working correctly. However...

I started to notice that sometimes (very randomly and sporadically) just one or two of the axis values would disappear. Furthermore other Label components not related to charts would also disappear, all seemingly at random and never more than just one or two at a time.

So, the question is: What's happening?

Seems to me like an underlying embedded font problem, but what? And how to fix it?

Thanks

Upgrade to Flex SDK version 4.6