I just ran into this issue, clearly it is old and Python 2.6, but I just experienced it in a single-process linux app running on a production embedded system.
root@at91sam9g20ek:~# python
Python 2.6.5 (r265:79063, Sep 28 2011, 11:52:59)
[GCC 4.3.3] on linux2
The symptom is the original "ValueError: I/O operation on closed file." I see one log file that has reached its max size and never rolls over and as a result, the app is unable to log anything.
Has anyone since experienced related issues that could exhibit this behavior?