I recently upgraded Flash Builder from 4.5 to 4.5.1 on Mac OS 10.5. Ever since then every time I try to compile any previous projects, nothing is rendered. The swf runs and if I run it in the debugger it hits all the proper breakpoints, but nothing is visible on screen. I've tried following the migration instructions for projects but this persisted after uninstalling and reinstalling both Flash Builder and the player several times. I then upgraded to OS 10.6 and tried it all again, but the still the same. I've tried following the migration instructions for projects.