I am happy to come up with a minimal test for this if that would help, but repeating the problem is not hard. Take a Python2.7 interpreter, install the decorator module from PyPi, and also the code at https://bitbucket.org/tleeuwenburg/benchmarker.py/. Running test_benchmarker.py will cause the problem.

Exception TypeError: "'str' object is not callable" in '/tmp/benchlog/2011/30/2011_03_30_09_41.pstats' ignored

I've tracked this message down and it's likely being writted to stdout by errors.c, where unraisable exceptions are handled.

Using hotshot, and otherwise the same code, the error does not occur. Diagnosing the true cause of this issue is probably beyond me, but I'm more than happy to try to come up with a more minimal example or help any way I can.