logging python python-3.x

PermissionError when using python 3.3.4 and RotatingFileHandler

I am trying to get a rotating log file for a GUI application I am writing with python 3.3.4 and PyQt4.

I have the following snippet of code in my main script:

import logging
import resources
logger = logging.getLogger('main.test')
def main():
fh = RotatingFileHandler(resources.LOG_FILE_PATH, maxBytes=500, backupCount=5)
formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')

I have the maxBytes low so that I can test the rotating is working correctly, which it is not. I am getting the following error whenever the log should be rotated:

Traceback (most recent call last):
File "C:\Python33\lib\logging\", line 73, in emit
File "C:\Python33\lib\logging\", line 176, in doRollover
self.rotate(self.baseFilename, dfn)
File "C:\Python33\lib\logging\", line 116, in rotate
os.rename(source, dest)
PermissionError: [WinError 32] The process cannot access the file because it is being used by another process: 'C:\\Users\\myuser\\.logtest\\test.log.1'

And nothing is logged. Any help is much appreciated.
Thank you