Why won't IE7 display buttons?

I have a strange problem. When using IE7 on one machine, buttons in fckeditor only display when moused over. On the same machine, FF displays the buttons just fine. To add to my joys, the buttons work on a friend's IE7 installation, and on IE6 on another machine. Does anyone have a clue as to what setting to change on my IE7 installation to allow the buttons to display.

Thanks for any help.

Howard