How did you exactly wire DMX-512 to that track.
You talk about using one conductor for it.
The DMX-512 is designed to be transported as a balanced RS-485 signal over a wire pair, so you need two signal wires (and also ground) to successfully carry the signal over significant distances.
Other thing to consider is how you connected the DMX-512 devices to that track, the DMX-512 should be a straight bus, is is not designed to be a wire bus that splits (like splitting signal wire out from bus many places).
And third is remember the correct signal termination at the far end of the bus. It is important for signal quality (especially when using long runs and/or non-ideal wire type).