Problem playing divx...

I bought a divx dvd player for my tv. I have put many files on it, i used winavi to make normal avi files to divx. However I made one disc and put a video on it. It played fine. I left the dvd open so i could add to later. then i added to it and now the player says unknown disc. it still plays the other divx videos previously burned. (they r mostly xvid but still plays fine so thats not the problem). is there a solution to this? i dont want to waste another disc burning again if there is another problem.

thanks in advance.

Darth Yoda