I have a similar problem. I installed the latest Thunderbird 2, lightning .7, and birdsyic 1.5.6.0. Now my cards and tasks are syncing correctly but everytime that the events try to sync Thunderbird crashes. I own the software and am a registered user. Can you help with this?
I emailed support yesterday and it turns out that I had a null value in my calender which was crashing thunderbird when events tried to sync. Thanks, J.