There is a serious problem with Firefox 3.5. When you have only one tab open in Firefox and when you close that tab, instead of opening a new, blank tab, Firefox itself exits. This is annoying because you would expect a new tab to open, but you see Firefox disappear in front of you and your heart sinks.
Turns out there is an easy fix for this.
1. Open Firefox and type about:config in the browser address bar. You will get a warning, acknowledge it and carry on.
2. In the filter, type browser.tabs, you will see some entries in the table. You will also see ‘browser.tabs.closeWindowWithLastTab’. Its value should be true. Right click on this and click on Toggle. The value should change to false.
3. Close the browser and open again.
4. Verify that the browser doesn’t close when you close the only open tab.