This is a weird one, wondering if anyone else has noticed this and if yes, what you did to resolve it. All of a sudden the code hinting for libraries (anything in the libs folder) stopped working in the Flex project I'm working on, even though it worked just a few minutes before. Nothing in the workspace should have changed since before it stopped working. I've already tried creating a new workspace and importing the project there, but the same thing happens. I also tried linking to the swc files manually through the project properties, but that didn't help either. The code hinting for the Flex framework and ActionScript files works, it seems it's just the libs that stopped working.
I can get it to work again by simply renaming the project to something that hasn't been used before within this workspace. If I change the name back to the original, then it stops working again.