Christine -
If you subscribed directly to the calendar from the iPhone settings application, it works around the problem. OmniFocus can't complete the process, but you found a different route to where you wanted to go. :-)
Just make sure to sync your phone once a day or so, and OmniFocus for iPhone will keep those calendar alerts up to date. (Eventually, we're going to add the code that does this to the Mac version, but right now, only the iPhone version updates the calendar file.)
If you subscribed directly to the calendar from the iPhone settings application, it works around the problem. OmniFocus can't complete the process, but you found a different route to where you wanted to go. :-)
Just make sure to sync your phone once a day or so, and OmniFocus for iPhone will keep those calendar alerts up to date. (Eventually, we're going to add the code that does this to the Mac version, but right now, only the iPhone version updates the calendar file.)