"Invalid Project Interpreter" even though execution works

Hey guys,

I have been using PyCharm happily for a while now but all of a sudden I get an error that it cannot run the Python interpreter from my virtualenv when I start the application: "Invalid Project Interpreter: Cannot run the project interpreter." It also marks all builtin symbols as not being able to be resolved. However, when I use the builtin run command to run the script (in my case a django app) it uses the interpreter I specified and happily runs my script in the virtualenv just as expected.
I already tried clearing the cache, have removed and re-added the interpreter and the python standard lib should be on the interpreter path.

I am running PyCharm 3.0.1 on OS X 10.9 with Python 2.7.5 in virtualenv 1.9.1. If I recall correctly the problem was also present on PyCharm 3.0.0 so I upgraded in hope of fixing the issue.

Would appreciate some help, Googled and read the online docs but found nobody else even mentioning this exact error. Log is attached.

Thanks,
Robin
idea.log (931KB)