Endpoint Protection Live Update Running too Frequently

We're running Endpoint Protection (version 11.06.6200) on numerous Macs (OSX 10.5 and 10.6), installed as 'self managed', and I've been getting complaints about how frequently Live Update is running by default. Even with zero items listed on the 'scheduled events', Live Update is running roughly 4-5 times each day (actually finding an update to download and install much more rarely). Worse, if I schedule my own updates, it just adds to the ones already running (e.g. Live Update runs 5-6 times each day rather than 4-5) rather than replacing the default schedule. I've tried using the terminal to run symsched, but it doesn't list any updates that the Symantec Scheduler doesn't (i.e. neither list any scheduled updates at all). Does anyone know how to turn down/off the frequency of these default Live Updates?