Quite simply there is no option that says Disable automatic updates. I know there are two options that allow you to specify if you want Comodo to update before scans, but I don't think those will stop random updates.
Also is there anyway to stop an update in progress. The only button on the update window is Hide.
I'm low on Internet download quota and desperately need a better option than 'Stop all activities' to block network use from everything.
Note: I'm referring to virus signature updates, not program updates.