500 Internal Server Error

The server encountered an unexpected condition which prevented it from fulfilling the request.

Traceback (most recent call last):
  File "C:\SickBeard\cherrypy\_cprequest.py", line 660, in respond
    response.body = self.handler()
  File "C:\SickBeard\cherrypy\lib\encoding.py", line 193, in __call__
    self.body = self.oldhandler(*args, **kwargs)
  File "C:\SickBeard\cherrypy\_cpdispatch.py", line 25, in __call__
    return self.callable(*self.args, **self.kwargs)
  File "C:\SickBeard\sickbeard\webserve.py", line 1807, in index
    return _munge(t)
  File "C:\SickBeard\sickbeard\webserve.py", line 97, in _munge
    return unicode(string).encode('utf-8', 'xmlcharrefreplace')
  File "C:\Python27\lib\site-packages\Cheetah\Template.py", line 1010, in __unicode__
    return getattr(self, mainMethName)()
  File "_SickBeard_data_interfaces_default_home_tmpl.py", line 288, in respond
  File "C:\SickBeard\sickbeard\tv.py", line 634, in nextEpisode
    sqlResults = myDB.select(query, params)
  File "C:\SickBeard\sickbeard\db.py", line 79, in select
    sqlResults = self.action(query, args).fetchall()
  File "C:\SickBeard\sickbeard\db.py", line 57, in action
    logger.log(self.dbFileName+": "+query+" with args "+str(args), logger.DEBUG)
  File "C:\SickBeard\sickbeard\logger.py", line 176, in log
    sb_log_instance.log(toLog, logLevel)
  File "C:\SickBeard\sickbeard\logger.py", line 144, in log
    self._rotate_logs()
  File "C:\SickBeard\sickbeard\logger.py", line 128, in _rotate_logs
    os.rename(cur_file_name, self._log_file_name(i+1))
WindowsError: [Error 32] The process cannot access the file because it is being used by another process