Flash Builder 4.5 - Can't import external classes?

Hi folks I just installed the trial version of 4.5 of flash builder, migrating from 4.0 and I am encountering quite a frustrating problem.

For some reason in which I can not peg, FB refuses to compile anything with an import from an external class, like greensock, bulk loader etc. I keep getting a 1172: Definition could not be found for any import from my external class AS3 folder on my harddrive.

Now I did edit my build path in the projec开发者_JAVA技巧t and include the AS3 folder there as I usually do in past FB projects. Even code hinting works when typing in the import lines and even making new objects from those imports.

But every time I save or try to compile, such errors appear on each one consistently. This is coming from a fresh install of 4.5 btw on any Flash Professional project and I would like to use it but I can't seem to get around such a fundamental problem.

What am I doing wrong?

All I can say buddy is to make sure that all of the files are in the same folder (may seem obvious, but it's an easy mistake to make).