Long one car type trains Options

[dispatcher]

With AG4, it is possible to designate tracks any way you choose. I have designated a few tracks as coal car only, both empty and loaded, duly marked in the TDB file. When I tell the program to take as many as 35 cars from one or more of these coal tracks as the source track and no work inbetween them and the destination tracks, I get a mixture of cars as if the track was designated as "A" rather than coal car only. More importantly, the rest of the source tracks have various cars sitting on them as though they were all marked as "A" tracks. They are all marked as coal cars in the TDB file. What is happening that I am missing?