Lightning 0.7 - all my existing events & data lost. Rated 2 out of 5 stars

Hi,
I was updating from 0.5 to 0.7 whenever asked automatically by Thunderbird's Updater.
After updated, suddenly all my data lost!
What i did now just to uninstall 0.7 and re-install 0.5 using its XPI file that I kept.

This review is for a previous version of the add-on (0.7).