s950 midi please help!

I know it's been mentioned before, and everyones like yeah just plug the midi cable in. But I've tried on my 2000xl and 3000 and can't get it to register shit. As soon as I plug in my ASR the 950 receives the midi straight away, no mucking around. I've gone into the midi menus and shit and can't get it sussed, am I missing something? I wanna do all my sampling in the 950 and use my 3000 to trigger/sequence, but I'm starting to get frustrated. Any help would be appreciated.

go to the sequence track menu and turn on the desired midi channel (down in the left of the screen in the 2000) turning the data wheel clockwise (page 28 of the 2000 operator's manual http://www.autistici.org/2000-maniax/texts/MPC2000E.pdf )
don't know if it is the same on the 3000