caldav calendar is empty - unable to add new either

[ciara belle]

mac os x.6.2
tb 3.0 (non-beta)
dec17th build of lightning

i added a google caldav no problem

then i attempted to add a kerio mailserver caldav (works fine in
ical)...

after several hours of ts to try to figure out how to get lightning to
trust our internal mailserver certificate (thanks to the person in
bugzilla that posted his steps to force the cert to be trusted)... i
finally got the caldav added to the point where it asked for un and
pw... yay -- i was ecstatic

fast forward a few hours -- there are quite a few events in the
calendar so i thought i would just let it run in the background and
update... i check the calendar -- nada - no events...no tasks either
log into webmail verify all is well on the server - yup
i attempt to make a task.. u get a real vague "error when writing to
calendar dg" (dg being the name of the calendar)
details - modification_failed

hmm thats helpful.. not

so i attempt to make an event -- same issue

no idea what's going on -- no ! on the calendar - no connect errors --
and the mail is pretty much connecting fine on the tb3 side for this
server.

anyone got any ideas?

thanks
ml