Updates:
Status: Done
Comment #1 on issue 635 by pekka.klarck: Warnings from keywords are logged
twice
http://code.google.com/p/robotframework/issues/detail?id=635
The root cause is that warnings and errors written to the console are written to sys.stderr while the framework has captured output streams. A simple fix, done in r3996, is writing the message to sys.__stderr__ which always contains the original stderr.
