Rated 4 out of 5 stars

Thunderbirthday does not load with lightning .09pre
Error:Error: Can't create calendar for 9 (thunderbirthday, moz-abmdbdirectory://abook.mab): TypeError: cal has no properties
Source File: file:///C:/Documents%20and%20Settings/glenj/Application%20Data/Thunderbird/Profiles/bwxw18ox.default/extensions/%7Be2fda1a4-762b-4020-b5ad-a41df1933103%7D/js/calCalendarManager.js
Line: 712

This review is for a previous version of the add-on (0.2.7). 

Please understand that I cannot follow every minor change in the development of Lightning. I'll try to release a new version short before the final version of Lightning, when changes become less frequent. Also, you might try to just change the maxVersion value in install.rdf.