User-Agent: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; fr; rv:1.9.2.8) Gecko/20100722 Firefox/3.6.8 Build Identifier: Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10.6; fr; rv:1.9.1.5) Gecko/20091204 Lightning/1.0b2pre Thunderbird/3.0 The "Cache (EXPERIMENTAL, requires restart)" functionnality works fine when I use it on my Google Agenda OR when I use it on an iCal generated by a SPIP CMS website (webcal://www.***.com/***/spip.php?page=ical). But if I check "Cache" simultaneously for both sites, and I restart Thunderbird, then I got the same Calendar (either my Google Agenda or the other one) displayed twice (once with the right color and once with the color of the other calendar which is not displayed). It seems as if the "Cache" confuses the two sites. Reproducible: Always Steps to Reproduce: 1. Add two different "On the network" calendars to your agenda (one ICS and one Google Agenda for example) 2. For both calendars, click on "properties" and check "cache (EXPERIMENTAL, requires restart)". 3. Restart thunderbird Actual Results: After restarting Thunderbird, look in your agenda : you've got the same calendar (randomly one of the two calendars with the "cache" functionnality enabled) displayed twice, with two different colors (the two colors of the two calendars with the "cache" functionnality enabled) Expected Results: We should see the two different calendars, each one with his own color. And not one calendar displayed twice and the other one not displayed at all. This is only a display bug. If one of the two calendars get the "Cache" checkbox disabled again, and thunderbird is restarted, then the situation becomes good again, and the calendars have not been altered by the bug (I observed no accidental loss of data, though I didn't tried to modified one of the two calendars while the bug was active to double check if it can introduce loss of data) Obviously I have "Provider for Google Calendar" installed on my Thunderbird (plugin version 0.6b2pre)

In fact to get the situation good again, you need to uncheck "Cache" on BOTH calendars, restart Thunderbird, and then you may check the "Cache" functionnality on one of the two calendars (and only one), and then restart again. (it seems like the cache need to be completely flushed for the situation to come back to normal, before you can use the "Cache" functionnality again)

Already fixed in the Lightning 1.0b2 release. You'll have to upgrade to the latest Thunderbird 3.1.2 release to use Lightning 1.0b2.