Panel Position/Size change

Almost every time I boot, the panel (normally at the bottom of the screen) opens in a different position or a different size (width or height). Sometimes it is at the top, sometimes right in the middle of the screen. Sometimes it will be only about a half screen wide.

I installed 11.0 and KDE 4.1. I have a windscreen 1920x1200 monitor. That setting appears OK. I installed the Nvidia proprietary driver.