pycharm code completion works but inserts unresolved references

(First posted on http://stackoverflow.com/questions/19903420)

Using PyCharm 3.0.1 Community the code completion works fine, but when I e.g. compelete to a method to one of the parents classes, the inserted method name then gets marked as an unresolved reference. What am I missing?

Details:

I am new to PyCharm, and test it on a (unified installed) Plone 4.3.2. The interpreter from the Installation is selected automatically, and I add the zinstance/bin/zopepy script for buildout.

I then open Products.CMFPlone-4.3.2-py2.7.egg/Products/CMFPlone/SkinsTool.py and then type

    x = SkinsTool.

at the bottom of the file. The code completion offers me manage_changeProperties (and shows PropertyManager). All great so far. I select this, so that the finished line now says

    x = SkinsTool.manage_changeProperties

The manage_changeProperties part is marked though. Hovering over the marked 'manage_changeProperties' now shows

    Unresolved attribute reference 'manage_changeProperties' for class 'SkinsTool'

I have tested this also on a instance of SkinsTool (e.g. x = SkinsTool; x.manage_changeProperties()), and also with 3.0.1 Professional

The strucuture is the one of a standard plone installation: structure.txt. I have opened the topmost plone.4.3.2 folder.

Is this a bug or am I doing something wrong (e.g. with importing the project)?

Cheers, Joerg