I'm pretty certain that my research has shown that this problem is actually a result of Thunderbird built with support for GIO (disabled by default and not enabled in the mozilla release builds)
GIO actually uses GConf to lookup the url-handler which is why it still causes a GConf error, but Thunderbird doesn't own the GConf Client object, it only has a GIO Client in that scenario.
I'm pretty certain that my research has shown that this problem is actually a result of Thunderbird built with support for GIO (disabled by default and not enabled in the mozilla release builds)
This is kind of the opposite to comment #19 ( https:/ /bugzilla. mozilla. org/show_ bug.cgi? id=541130# c19 )
GIO actually uses GConf to lookup the url-handler which is why it still causes a GConf error, but Thunderbird doesn't own the GConf Client object, it only has a GIO Client in that scenario.