Ok, thanks to help from you guys it's ready to go! It still doesn't handle stacked walls great, it basically skips them and warns the user that it's doing it, but the pieces show up. Interestingly, they show up twice; once as a wall and once as a curtain panel. Either way, it doesn't create an error anymore and the program continues normally and all elements can still be selected. I also tested it on a large project and it seems to work well, albeit slow if there are really a lot of elements.
So Guy let me know what ADN says, but in the mean time, THANKS TO BOTH OF YOU!