...I am going to make this Rotel system hit if it kills me!!!!

Here is the system....

I implemented a T3/RP6/RM433 to control a Rotel stereo receiver driven 2 zone system via 232. Tivo series 3 (emitter), Denon DVD (direct IR input) and Apple TV (emitter) run through a Gefen 4x1 HDMI switcher (232) into a Pioneer Elite 1130 (232) utilizing a media receiver. All audio is analog stereo through the receiver.

My issue...

Before I implemented the HDMI switcher I had encountered 232 signal crosstalk in the audio system when controlling the receiver. It was especially evident when ramping the volume. I found that I could reduce this crosstalk substantially by connecting a ground wire between the ground pin of the RP6 and the lug on the receiver. After I implemented the HDMI switcher a high pitched noise entered the system. After troubleshooting I discovered that If I disconnected the ground wire between the processor and RP6 or if I disconnected the HDMI cables from all of the components or if I disconnected the 232 connection from the HDMI switcher. I tried many grounding schemes with no luck and found that as long as the control system, switcher and receiver were interconnected, the high pitched noise was present. I pulled the ground to the receiver and the client and I agreed to "make lemonade out of lemons" (his words) and revel in the fact that we had audio feedback of the volume control (Crestron move over!).

Any ideas?
Any experience out there?
Rotel anyone?

I would love to kill the crosstalk if at all possible.