I may be losing my mind. Running MS Word 2010 maximized on a 24" screen caused the document pages to automatically tile left and right. They are not columns or a split screen - just tiling using Print Layout mode.

I restored my OS drive to see if I had made any changes - I thought "Arrange All" in the View tab had messed up tiling but it was doing the same a month ago.

I don't remember this ever happening as it made it very difficult to compose a document. I just tried the same using Word 2003 and it does not happen. I've been using Word since I gave up on WordPerfect and got 5.x for DOS and don't recall this happening.

Thanks to all for reading my original post.