[Twisted-Python] Rotating logfiles (SIGUSR1 doesn't work)

Hi, we've written a server running as a twisted application. Logging is done via twisted.python.log.msg. The log file is growing rather big and only rotated on server startup, which hopefully is a very rare occurrence, indeed. Sending a SIGUSR1 to twistd unfortunately doesn't do anything. I've seen that the class LogFile has a rotate method but I don't see the connection between twisted.python.log and that class if there is any at all. Any hint would be highly appreciated chris