I don't know about watching the thread, I have only just found it.
It seems that the error can be caused by a fault on the disc, rather than the machine. All but one of the disks I have play faultlessly on MDS-JE530. The disc in question will play/record for a while, then throws the dreaded error up. The fault seems to be caused by the disc not spinning freely. I tried it in my little Sharp portable. That both records and plays it fully, though there are 'grinding noises' several times during both (which I don't seem to get to the same degree on any other disc).
Also, I presume the C13 error will sometimes be generated if the laser lens is dirty.
A service manual is available from Manuals.lib.