[zsteir]

Update: I put this to OP support, and they came back quickly with a response. (Thank you). They suggested checking the time-zone support in iCal, but that wasn't the problem.

To those of you who are following, I think I've isolated in the following way (which I just wrote to support about):

1) If I delete all subscribed calendars, the export into ical works fine, with each resources getting its tasks assigned in iCal only during the hours in which that resource is available.

2) Once I subscribe to an off-hours calendar from iCal (setting the off-hours to affect the entire project), both resources get assigned to the FULL work day minus off-hours from the subscribed calendar, but without accounting for each resource's available times as set in their own work OP calendar. So the problem returns.

3) If I subscribe to an off-hours calendar from iCal but set the calendar to affect only a single resource (not the whole project), the problem disappears once again, and times are assigned appropriately.

This suggest that the Project setting under the subscribe to iCal option in Subscriptions setting is the culprit here. It is causing OP to ignore the individual resources calendars.

Just FYI.