After installing Lightning 1.05b, I installed the Google Calendar provider v0.8 in Thunderbird 6.0.2, and then added 3 Google Calendars, using the XML URL.
Only one of them appeared in the calendar's Day view. But when I switched to the Multiweek or Month view - all three calendars were visible.
So I just assumed Thunderbird got confused. After restarting Thunderbird, only one of the calendars was visible in any of the views.
I've tried removing and re-adding the calendars, I've tried using the iCal URL instead of the XML URL. Nothing seems to work.
Am I missing something simple?