User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:18.104.22.168) Gecko/20090824 Firefox/3.5.3 Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 6.1; de; rv:22.214.171.124) Gecko/20090824 Firefox/3.5.3 The URL field can't be used for a new website, if you have opened this tab while you was in fullscreen mode with an other tab. Reproducible: Always Steps to Reproduce: 1. Maximize a tab with F11. 2. Press CTRL + T to create a new tab. 3. Minimize tab by pressing F11 again. Actual Results: You can't put in the url field a new link, it's all grey. Expected Results: Accepted the input as a new url.