Spider has been updated to 0.0.2.6. This update adds the command line argument uri as a synonym for url to work around a bug in Thunderbird which tries to process any command line argument named url as a mailto url.
This will allow Spider 0.0.2.6 or later to be used in the “download checker” tool to download, install and report on Thunderbird 2.
Current users of Spider can simply update. New users can install from spider.xpi.
Thanks to Scott MacGregor for finding and fixing the problem.