i have the flame device with b2g 220.127.116.11 kompilation: 20140809160202
to my problem: i have connected to my caldav calendar on my arkos (raspi distro). all events are shown, i can create events but i can not delete them. when i tap the delete button, it just flashes, and does not switch back to the overview and the event is still there. it is a normal http connection (non https).
i can delete the events with other clients. for example evolution.
I have the same symptom and also there are other entries in the forum mentioning the same problem.
There is a bug report open that describes the problem (https://bugzilla.mozilla.org/show_bug.cgi?id=943840).
If your symptoms match this, you could add your information to it.