Random traceback

[user at domain.invalid]

Is there any condition that would cause the following traceback:
++++++++++++++++++++
Traceback (innermost last):
   File "/tmp/multimeter.py", line 157, in ?
     myLogger.logMessage(message)
   File "/tmp/Logger.py", line 46, in logMessage
     self.__logToSyslog__(message)
   File "/tmp/Logger.py", line 85, in __logToSyslog__
     syslog.syslog("%s" %reading)
TypeError: [priority,] message string
++++++++++++++++++++