I have found a small problem with the lua edu tools.
If you declare and install two images for the same object in infoImage.lua that are not the same vertical size (ie.: 256 x 256 and 256 x 512) you will get a strange artefact where the image switching buttons are located when you select More Info in the Edu Tools user interface and then select the other image. The artefact will appear in the taller image.
See image below. Notice the two vertical greenish looking vertical stripes just below the arrow switches. Depending on the image colour, the stripes will be more evident or wider if the image is 512 pixels wide.
This problem appears on my system consisting of Windows XP all updates, GeForce 8800 GT with updated drivers and Celestia compiled from revision 4954 with Visual C++ Express Edition with latest updates.