Arrow keys for movement

I have always and always intend to use the arrow keys for movement.  Suddenly today, they mysteriously now function as "look" instead of "move."  WHY?  They have always done this in vehicles for some odd reason, but suddenly today while I'm on foot as well.  I played for hours last night just fine, and all of a sudden this.  What have you broken now?  I tried the same workarounds for the mouse bug but that didn't work.