Rated 4 out of 5 stars
See Finally Lightning worked by Johnson on August 15, 2011
Installing 1.0b5 on TB6 was successful, but after restart Lightning has gone from addons. I repeated this 2 times, no result.
I restarted XP Sp3 in safe mode (I think my ZA PRO firewall and AVG 10 free don't run in this case), and finally full success, I can work with Calendar in normal mode, my data is intact.