First, check to make sure that your image files are in the .bmp format and are 8-bit color depth. DirectRT tends to work best with images of an 8-bit depth. It's not too difficult to do this conversion. Here are the steps, which you can also find in here in the online DirectRT manual (http://www.empirisoft.com/directrt/h...mage_files.htm):
1) Donwload the free program IrfanView at http://www.irfanview.com/.
2) Open Irfanview and open the image that you want to change.
3) From the Image Menu, select Decrease Color Depth.
4) Select 256 colours and save your image.

If the problem still persists, I'd like to try to run the files on my copy of DirectRT. Please get a copy of the all files I would need to run it in DirectRT and either upload them here or send them directly to support@empirisoft.com (and mention case 29572).