|ClamTray is an essential intergated component of clamwin. It is responsible for running update and scanning schedules, balloon reporting etc. Disabling it will do more harm then good.
That's why I asked for an option (maybe under an "Advanced" tab). I personally don't need it, and have to disable it manually every time after upgrading. I do not do scans often, and I update the database when I want to do a scan. If ClamTray used less RAM, maybe I would leave it, but 17MB seems too much to me.