Hi Ron, that's mysterious. When you say --

BubE said

Hitting the PAGE DOWN key takes me down a page, but also highlights the URL window. Hitting it a second time has no effect. A third hit takes me down another page and highlights the URL window again. A fourth hit has no effect.

-- do you mean the "focus" -- where the cursor appears to be -- is moving back and forth between the document and the address bar, as though you were using the F6 function key?

Regarding this one --

There is another navigational oddity at these two sites: holding the arrow down key, produces a smooth steady navigation down through the web page, but holding down the up arrow key produces only a move upward of one line; to move more than one line upward, I have to press the up arrow key repeatedly.

-- could you check that "caret browsing" is not enabled? Here's where you do that:

(1) In a new tab, type or paste about:config in the address bar and press Enter/Return. Click the button accepting the risk.

(2) In the search box above the list, type or paste caret and pause while the list is filtered

(3) If the accessibility.browsewithcaret preference is bolded and jas a value of true, double-click it to restore the default value of false (if it already has false, I suggest double-clicking twice to make sure it's really false)

Did you try to close and restart Firefox or reboot the computer ?

To answer the question, the pressing the PAGE DOWN key creates the same sequence of actions as pressing the F6 key.

As for the suggested fix involving the accessibility.browsewithcaret preference, this was set at false. I did the double double-clicking and the same problem was present. Should I have restarted after completing this task? I did not do that.

Thanks for your help.

Ron

Thanks for checking the caret browsing, which affects how the arrow keys move through documents.

Your Firefox seems to be confused about your keyboard input. If a system shut down and restart doesn't help that, you might need to reinstall Firefox. I think that involve dragging the Firefox.app file from the Applications folder to the trash and then installing from the DMG file again. However, that's very second hand since I'm a Windows user.

You might want to make a backup of your data just in case: Back up and restore information in Firefox profiles.

I tried the restart and the same problems continue. I may try to re-install, but I'm reluctant to do anything that requires a backup, because of the risks that seem inherent in that. Thanks. Ron

I've never heard of caret browsing setting focus to the location bar, that is why I suggested a reboot in case some keys were stuck. Also I don't think that F6 works on Mac the same as on Windows and Linux to switch focus between the web page and toolbar area or has this changed or do you mean fn + F6?

Hitting the F6 key by itself takes me from the page to the URL window while moving me one page down. Hitting it a second time takes me back to the page. Successive hits repeat this sequence.