Brower & viewer --> Horizontal
Somehow while working on a slideshow in Viewer mode with the strip horizontal below the main image, it got flipped so that the strip is now vertical tothe left of the window. I cannot figure out how to restore it back to horizontal below main window. should be so simple!!! but stuck!
OK, after Force Quit and relaunch things are back where I want them.
MacBook Pro, OS X Mountain Lion (10.8.3), 8GB SDRAM; 750GB HD