Can I make tasks imported from the calendar so they can't be changed?

Wow, WeekPlan is almost exactly what I've been looking for. Thank you!

One stumbling block from this brand new user, though. When I pull Google Calendar events in as tasks, and then I re-arrange the tasks for a day, it actually changes the time on the "tasks" imported from Google Calendar. Is there a way to prevent this?

I would like to treat my calendar as the "fixed" tasks, and stuff entered directly into WeekPlan as the stuff I will do in the spaces in between. WeekPlan is _almost_ perfect for this, but if I accidentally drag one of my Google Calendar events, it gets set to a completely different time!