I have the same problem with a program I'm writing.
The attached script is made using parts of it's code.
The logger is set up using a configuration file.

By the way, the error is:

Traceback (most recent call last):
  File "C:\Python26\lib\logging\handlers.py", line 74, in emit
    if self.shouldRollover(record):
  File "C:\Python26\lib\logging\handlers.py", line 146, in shouldRollover
    self.stream.seek(0, 2)  #due to non-posix-compliant Windows feature
ValueError: I/O operation on closed file