How do I stop my calendar subscribers getting my alarms?

I publish my work calendar and my colleagues subscribe to this calendar. The problem is when one of my events has an alarm everyone who is subscribed to my calendar also gets the alarm. There doesn't seem to be a way to turn it off.

We are all on Lion 10.7.2 and use iCloud to sync our calendars.

Is anyone else having this problem or worked out a solution?