What happens when you click the list button? It works for me in both a regular and private window (there's a slight difference in the screen shots, possibly due to Facebook being blocked in the private window).

Could you test in Firefox's Safe Mode? In Safe Mode, Firefox temporarily deactivates extensions, hardware acceleration, and some other advanced features to help you assess whether these are causing the problem.

If Firefox is not running: Hold down the Shift key when starting Firefox.

If Firefox is running: You can restart Firefox in Safe Mode using either:

• "3-bar" menu button > "?" button > Restart with Add-ons Disabled
• Help menu > Restart with Add-ons Disabled

and OK the restart.

Both scenarios: A small dialog should appear. Click "Start in Safe Mode" (not Refresh).

Any improvement?

Re-starting in Safe Mode solved the problem. Next I re-started in normal mode and the problem was still solved. I am a moderately advanced user with maybe 10 add-ons and plug-ins.

What I don't get is why my friend with 32-bit XP had the same exact problem. She is a definitely not an advanced user and probably only has Flash or Java installed. Odd. I will pass this on to her and see what happens to her installation.

Thanks for the quick response!