Playing psr-S950 with master keyboard

[GoJoe]

New member here.  I've been happily playing my psr-S950 for over twelve years and have been very pleased with it.  Recently I bought a P525 and have been enjoying both the realistic piano sounds and the incredible feel of the keyboard - feels like playing an acoustic piano.  Ideally, I'd like to link the two together via midi and use the P525 to trigger the 950, especially the rhythms and bass.  I tried running a midi cable from the midi out of the 525 to the midi in of the 950 (using the Master KBD setting on the 950).  Playing the 525 will play the same notes on the 950 (as well as on the 525), but will not trigger the registrations (drums, bass, etc.) What I'd really like to be able to do is to trigger the 950 registrations with the 525 without having it also play all the other notes I'm playing on the 525.  Does anyone have any suggestions on how to accomplish this? 

Additionally, my messing around with all this has caused a malfunction in the psr-S950.  When playing registrations, the bass note remains on C no matter what chord I'm playing (either on the 525 or on the 950 itself).  Have I fouled up something with all my button pushing, or does it sound like some other malfunction in the S950 itself?

Many thanks for any assistance offered.

Joe B.