User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9pre) Gecko/2008042606 Minefield/3.0pre Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9pre) Gecko/2008042606 Minefield/3.0pre After a gap of 5 days I updated to latest nightly. Now keyboard navigation on many pages stops working after I move forward or backward. I return to a page in my history, and space to advance, PageUp, PageDown, and arrow keys all do nothing. Weird. Reproducible: Always Steps to Reproduce: 1. Visit a page like http://lists.freedesktop.org/archives/xorg/2008-April/date.html. Also http://forums.mozillazine.org/viewforum.php?f=23, even http://www.mozilla.org/projects/minefield/ 2. Click a link. 3. Return to the first page using Alt+Left Arrow, or back arrow in toolbar, or History > Back. 4. Now try to navigate the page with the keyboard: Space, arrow keys, PageUp, PageDown. Actual Results: No keyboard navigation to advance the web page works. (But tab to advance to next link, Ctrl-F or / to search work all work.) Clicking in the page doesn't help, nor does switching to another tab or window. The workaround is to reload the page (Ctrl-R). But this bug makes pages in Firefox feel dead, hence major severity. I sometimes see Warning: reference to undefined property this._lastLocation.port Source File: chrome://browser/content/browser.js Line: 7454 in the Error Console, but not exactly on these steps. Expected Results: Scrolling the page using the keyboard should work. My only add-ons are: Adblock Plus 0.7.5.4 (I tried disabling this, no change) ChatZilla 0.9.81 (wasn't open) Nightly Tester Tools 1.3