430978 - scrolling web page from keyboard is broken after Back/Forward

Status: RESOLVED DUPLICATE of bug 430723

(Firefox :: Keyboard Navigation, defect)

Description

[skierpage]

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