Flex 3 - Unable to resolve resource bundle error

While implementing Flex ResourceBundle using .properties files, I ran into a strange problem. Although my Locale folder was added to the build path, Flex could not find it and could not resolve the ResourceBundles. I Googled things up and found the problem, it looks like a Flex 3 issue...

Instead of specifying the locale folder in the build path (which sounds like the correct way to do it), add it to the "Additional compiler arguments" in the project's compiler tab.

To do this, simply right click your project > properites > Flex compiler and add "-source-path ../locale/{locale}" to the Aditional compiler arguments text field.

(note that my locale folder is under /locale/en_US/)



Once your done you'll be able to use this very powerful feature.
Note that in case you are using Ant you would also need to add the locale folder location as source-path path-element to the tags:

<mxmlc>
  .
  <source-path path-element="locale/{locale}"/>
  .
</mxmlc>