Here is my setup:
Various Sony HiFi components (receiver, tape, cd, etc.) and a Squeezebox3, located in the family room. I like to control them via RF with a MX-3000, MRF-300/RFX-150, and individual flashers. All of it stacked closely together in a HiFi rack.
The Sony components work just fine, however the Squeezbox3 gives me grief. It is not responsive to the commands coming from the MRF. It either hangs or does not respond at all.

Here is what I have done thus far:
- I have a similar set up in my home theater in the basement (several AV components, another set of MX-3000, MRF-300/RFX-150, including a Squeezebox). There, everything (hardware, codes, etc.) works just fine, no issues at all. I have swapped all URC components and Squeezebox around individually (the family room components with the ones from the basement): all components work fine when in the basement, but have issues when in the family room. To me this means that the hardware is ok, as well as my programming.
- Verified that I can control the Squeezebox via IR directly from the MX-3000 - this is in the family room
- Switched between various RF channels – issue persists.
- Verified that the LED in RFX-150 only lights up when it gets an actual signal; it remains dark otherwise - no glowing
- Moved Squeezebox, MRF-300, and RFX-150 around. There I found that the location of the MRF-300 seems to be key, not of the RFX-150 as I had suspected. I found that if I move it in the middle of the room the setup works find. However, this is not an acceptable solution. I could find a spot for the RFX several feet away from the HiFi rack area, but this does not really work for the MRF-300. Too bulky and too many cables/extensions I would need to run. My wife would kill me, if I did this…

What puzzles me is that the Sony components work just fine in this environment, but not the Squeezebox.

What else can I try?

Thanks!

On the top of the MRF-300 there are IR Adjustments, Lower the Adjustment. The IR blast might be too much for the Sqeezebox

Thanks, but I have tried that already. I also tried different ports (1-6) . I also tried various RF gain settings, incl. taking off the antenna.

It's possible that other flashers in your stack are causing the overload. Try putting a blanket over the squeezebox as a test to see if something else is getting into its window.

Tried it - issue persists.

In the meantime I have made some progress: putting the base unit (MRF-300) in an old sheet metal box, sandwiched between 2 aluminum drip pans from my Weber grill seems to provide enough shielding..... I only hope that this can't be the only solution. WAF is kind of low..... I am surprised that the MRF-300 seems to be so sensitive against electromagnetic (?) fields, which seem to cause this issue. The RFX-150 at the same spot is doing fine (does not glim).... That does not sound right... Am I missing anything?

That sounds about right for the URC...the pans. Cover them up with a few plants to get the WAF your looking for, I have had many similar issues as you installing URC we would get 1 room 100% but then move to the next room to only get at best 50% response. spend several hours to several days trying to correct the issues to only get another 25-30% better, we have found that changing the RFX150 to a RFX250 antenna has helped in most cases
also make sure your front blaster is off

Amen. This has been a problem in the past, after countless hours of testing, only to find that the front blaster is overpowering one or more components.

Good answer!

Front blasters were/are off.
It really seems to come down that some EMI in this particular area throws off the base unit. Shielding seems to do the trick - not pretty but it has been working thus far.