User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0 Build Identifier: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:2.0) Gecko/20100101 Firefox/4.0 As reported in bug 254714 comment 101 and reproduced by myself. Reproducible: Always Steps to Reproduce: 1. Go to http://twitter.com/firefox. 2. Find the link to Firefox's website on that page, and look closely at the address bar while clicking it. Actual Results: For a second or two (depending on network latency etc) you'll see "about:blank". Later it changes to the correct URL, but if you either cancel the request or just can't connect right now, you lose the target URL. Expected Results: The URL bar immediately shows the correct URL. Pressing Esc at any time must keep the URL, so that it can be reloaded.

This also happens in Snow Leopard and Linux (Ubuntu 10.04). How do I change the "Platform" above?

Oh sorry, I should have set that one. Fixed.