Post window too wide in 2.5

Just upgraded to 2.5 and it is wonderful . . . except for one little problem.
When I go to write or manage a post or page the writing window extends across the screen. The “tags” “excerpts”, “category” windows are all about halfway across the screen, but this one goes clear across.
The problem with this is that it goes under the “Publish Status” window and I cannot see the buttons. Also, it blocks the Save button etc.
I can grab the handle of the window in the lower left corner and drag the window vertically, but not horizontally.
I am not sure how well I explained this, but could someone offer some advice on what to try?

Thank you,
David