>I checked them, and they are all set to opaque. I also tried putting in "This.zorder(1)" in the INIT method for the shape, and nothing changes. Any other ideas?

The only other idea I have would be related to the video driver. Try switching your video driver to a generic one and see if the problem goes away. If it does then it is a problem with the video driver, if the problem is still there with a generic video driver then the driver is not the issue.