When I'm in the compose message box and click on the Preview tab to preview my post, the entire right-hand panel moves to the left and obscures half of the remaining screen.

By right-hand panel, I mean the vertical space that has "Welcome USER NAME" at the top, followed by "my profile" and "search community" and then myriad ads.

This is happening on a brand new Dell, Vista, Firefox (latest) and a 2 year-old iBook, OS X, Firefox (latest). 

Hi Linelle, 

I just tried the preview, and it does it for me also. There is a horizontal scroll bar at the bottom, so you can see your whole message by scrolling right or left. I will let the online people know about this.

Thanks!
 

 Hi Linelle,

I just got word from Lori, one of our wonderful online people, that the preview feature is working now.

It's true! Thanks to you and Lori and all the rest of the debuggers.