we used to add some subdirs of our project (and the project dir itself) to the modules classpath. When doing this with IDEA 9 (I imported older projects) the usage search is not working any more. No errors occur and no usage is found.
I tried to add the dirs as module dependency or as library, both the same effect. Everything worked fine with older versions of IDEA (e.g. 8.1.4), even with the IDEA 9 Beta release(!) I used before.
Is this a bug or how can I obtain the old behaviour?