Record Track Mute in JJ OS 3.12 MPC1000

I've read in multiple threads that its supposed to work but when i do it it never records the mutes.
Pressing REC+PLAY/START and then going into TRACKMUTE doesnt work for me. Am I missing something?

http://www7a.biglobe.ne.jp/~mpc1000/chart.htm

look at the "Recordable Track Mutes" line.

PEace