michaeldcohen, with the iCalendar Events feed, we set the duration of each event to be 1hr so that all tasks display on the calendar. The reason for this is that not all tasks may have time estimates, and that the time estimate for a task isn't necessarily the same as an event duration (e.g. if a report is due at 9am and has a time estimate of 6hrs, this doesn't mean that it should show as an event for the 6hrs immediately before or after the due date -- the report may be worked on at any time). Hope this helps!

Thanks Emily. I can see that you are kind of stuck. There really needs be a distinction between event duration and task duration. And you are running a task management system, not one primarily for events (appointments).
The setup does mean that I can't easily use RTM to enter appointments into my iCalendar, since I have many that aren't 1 hour. And I can understand that introducing a clearer distinction of events from tasks would be a burden on the code and the users.
I like the interface and other functionality you've provided in RTM, so I'll still keep using it, and just live with less integration than I'd hoped for.