.ics url iphone auto subscribe calendar
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I'm trying to create a url that allows me to auto-subscribe to a calendar that's being served by Radicale.  It works when there's no calendar already there (it just creates it), but when there's a pre-existing calendar it doesn't work.  I'm trying to get the "Would you like to subscribe to this calendar" dialog, have it load into the calendar app, and then synch the events as they change on the server.  I can add it manually as a CalDav calendar, but not a subscribed calendar.  

There is no authentication, it's a public calendar.

Here are my questions:

1.  Is this something that is supported by iOS?  I'm running iOS 5.  I've read that it worked prior to iOS 4.1, but stopped working after that.
2.  If it is supported, what might I be overlooking?  

Here are the url's I've tried:

    http://public@192.168.0.123:5232/test.ics/
    webcal://public@192.168.0.123:5232/test.ics/
    http://192.168.0.123:5232/test.ics/
    http://192.168.0.123:5232/public/test.ics/ <- after moving files into /public_user
    http://192.168.0.123:5232/public_user/test.ics/ <- after moving files into /public_user

I've also tried removing the trailing "/".

I've validated the calendar using http://icalvalid.cloudapp.net/Default.aspx


Any help would be appreciated!


