I just started getting these messages a few weeks ago and finally found the source of them. Now I'm reporting them and trying to find out why they appear. The appear on the console/xterm/konsole where I start Firefox (current production version) on my Fedora 16 x86_64 system. I'll leave the priority of this ticket as normal since I don't know how bad things are with this bug, IF this is a bug. Can you let me know what to do about them please? Here's a few of the messages: uri.host is explosive! (about:blank) Could not check applicable rules for about:blank uri.host is explosive! (about:blank) Could not check applicable rules for about:blank uri.host is explosive! (about:blank) Could not check applicable rules for about:blank uri.host is explosive! (about:blank) Could not check applicable rules for about:blank uri.host is explosive! (about:addons) Could not check applicable rules for about:addons uri.host is explosive! (about:addons) Could not check applicable rules for about:addons uri.host is explosive! (about:blank) Could not check applicable rules for about:blank **Trac**: **Username**: grgoffe