PyCharm: "unresolved reference" for "object", "isinstance", etc.

I am using PyCharm with python 2.7

PyCharm shows an "Unresolved reference" for things I believe are keywords or part of the Python language. For example:

class MyClass(object):
    pass

      

        
        
        
      

    

PyCharm states that "object" is an "unresolved reference" displaying an error sign. Similarely, "isinstance" and many other built-in methods don't seem to be resolved.

EDIT:
It looks like the problem is with the definition of the Python interpreter. To be able to send an IML file (where the path to the interpreter is stored), I created my own python interpreter named "MyPython" and set it to point to the interpreter on the machine. This interpreter does not have a path in the name (as it differs between machines) and it is not the one automatically generated by PyCharm. I only see this behavior when I am on MyPython. When on the generated PyCharm, that is: "Parsing Python 2.7.8 (C: \ Python27 \ python.exe)" is fine. Looks like a bug in PyCharm?