Stepping through folders with keyboard arrows is not displaying folder contents

This is in the Vista Windows Explorer view with the left pane showing folders.

As I move down with the arrow, the contents of the last folder I selected with the mouse continues to be displayed. The up arrow also misbehaves but the left and right buttons are doing what they should, jumping up to the parent folder or expanding or collapsing the selected folder. The two pictures show what's happening; note the address bar stayed the same when I used the arrow key to navigate to the "All" folder.

Is there a setting that stops the selected folder contents being displayed or is my computer just acting up?

====
As an aside, I use NoScript and AdBlock Plus in Firefox and something is blocking MG from displaying suggested threads similar to my problem based on the title I supply. It's not the majorgeeks.com domain - I have that allowed in NoScript. Nothing else obvious appears to be making any difference. I've attached a picture showing the domains listed. (If anyone knows of a thread that answers my question, I'd appreciate pointing to it; I failed to find anything via Google.)

 

I'm running Vista Ultimate and if the folder in the left pane isn't expandable (has a plus sign) using the right arrow won't show the contents of the folder. You have to press the Enter key.

In your last screenshot, MajorGeeks.com is forbidden.

 

The right arrow is fine; it does what it should, which is expanding folders. The problem is that moving around the left pane with the up and down arrows that doesn't make anything change in the right pane but it should and did up till the previous time I used this function.

I take it you don't use NoScript? The menu (pictured) shows you what you can do at this point in time. If I have the option to forbid Major Geeks, that's because it's currently allowed. So that screenshot shows that scripts will be allowed from Major Geeks on this page but no other domain. Anyway, that's not really bothering me; it's just a minor annoyance. The folder issue is a real pain.

 

And that's enough to have the title used as a search so you're offered threads as suggestions?

 

What I'm referring to is when you start a new thread. You type into the title box, switch out to the message box and suggestions come up between the title box and message box. Only they don't for me, though they used to.