How is your icsCalendar attribute formatted, is it:
icsCalendar: calid
..or..
icsCalendar: calid@domain.com
In uwcauth.properties check what you have for the "virtualdomain.mode" setting. Set it to:
y - if you have icsCalendar: calid@domain.com
n - if you have icsCalendar: calid
Then stop the web container and clear the uwc class cache:
cd /opt/SUNWwbsrv/https-instance/ClassCache/https-instance
rm -rf uwc.
Then restart the web container. If you still have problem, can you let us know if you can see the calendar tab in UWC and what happens when you click on it?