In nsGlobalWindow::Close() [1] an nsIScriptError message is logged, without any origin URI. This prevents the Web Console from showing the "window.close() blocked" warning, since it cannot associate the message from the console service with any open tab. The comment in the source code suggests that it's not clear which URI should be used. I would suggest that (1) the URI of the script which invoked window.close() should be used. An alternative would be (2) to use the source document location URI that holds the script in question. If option (1) is used .... we will still lack the ability to show the message *cough*, because we cannot easily track in which tab a specific script caused the warning message. There might be multiple pages with the same script, in different tabs. However, that would be a different bug - see bug 603706. [1] http://mxr.mozilla.org/mozilla-central/source/dom/base/nsGlobalWindow.cpp#5840

This is fixed by the patches from bug 606498.