Lightning 0.9pre (2008060420) + Thunderbird 220.127.116.11pre (20080605) on WinXP In Mail Mode the menu entry "File -> New -> Calendar" is disabled but creating new events and tasks is possible. One need to switch to Calendar or Task Mode to enable it. I don't know if there is a reason for this behavior but the current situation just confuses users, e.g. <http://forums.mozillazine.org/viewtopic.php?t=662701>
Created attachment 327309 [details] [diff] [review] Fix v1
Comment on attachment 327309 [details] [diff] [review] Fix v1 r=berend
Checked in on HEAD and MOZILLA_1_8_BRANCH -> FIXED
Checked in lightning 2008070305 -> VERIFIED.
Related to this fix, Bug 459356 , shows a problem where the File -> New -> Calendar option is disabled in all modes.
Anyone following http://hg.mozilla.org/mozilla-central/rev/3f8ae66d0015 (landed with this bug number), see Bug 537451.