Hi--- I have my 950 setup fine and it controls all components as expected. I'm now trying to set up an mrf250 using only the plug-in flashers and only rf out of the 950. Here is the way I have it set up as a test for only one device (my cable box):
In the rf setup in the 950 editor for the device CABLE, I have RF only chosen for the signal and ALL chosen for the flasher. I have a plugin wire hooked to the back of the mrf250. On the receiver menu I have the front blaster OFF. When I activate a command for the CABLE device on the 950, the mrf250 receives the signal and the red led on the end of the wire flashes. However, no matter how close or far away from the cable ir-receiver window I place the flasher, it does nothing. I have tried this with other devices as well. I guess I'm doing something incorrectly, but cant figure out what.
Any advice ?

I figured it out. The software defaults to id #1, yet the mrf250 was set to #0. Now it works.

Just an FYI in case you didn't know...your base ID and programming should match and NOT be set to 0 (zero is a test ID).

Thanks Tweeterguy..I did change them both to 1. But I was premature in touting my success. I had turned the front blaster on and the success that I thought I'd had was from the front blaster..
It appears that none of the flashers work at all. They do not light up and they do not seem to transmit anything to any devices when I cover up the front blaster. The front blaster is pretty darn strong and I may not need the flashers anyways, but it would be nice if they worked. Is my mrf-250 unit defective or is there something else I should be doing ?

Anybody have any suggestions ?

Check your RF routing in the programming. Make sure that the ports are assigned properly and set to RF not IR. The front blaster should be a last ditched effort to get this to work. Make sure the IR emitters are fully seated; I've seen a few times when techs push them in and think they are fully seated and they are not. Are you using the OEM emitters that came with the mrf kit? If not, not all emitters "blink".

Make sure that your ir emitters are plugged in all the way. I see alot of people not plug them in all the way.

Thanks Tweeterguy-- All routing is set to RF only for each device and each device is set to ALL for the flashers (I'm going to try setting each to a particular line). I've tried two different wires and have really pushed them in all the way, also two different lines.
One odd thing: When the mrf250 was set to ID 0 and in the remote software it was set to ID 1 (an accident), the emitters (OEMs that came with) would flash a visible light when a button on the remote was pushed. Since I have both software and mrf250 set to ID 1, the emitters do not flash a visible light, nor do they do anything to any device. At any rate when I get home tonight, I'm going to double check everything again one last time.
I want to get this working since the front blaster seems to be hit or miss, mostly hit, but its frustrating when its intermittent. I have a gut feeling that this is NOT a case of a faulty mrf250.

I now have success ! And despite the fact that I said the emitters were seated all the way, they were not. I really had to give them that extra push. Thanks for the help JTodd and TweeterGuy--you guys called it !

LOL...Seen that one coming a mile away :-)

I have another question. I now have everything set up as I wanted. All of my devices are a few feet behind the seating (front projector system) . I can turn my head around and see the lights on the front of the mrf250. Most of the time remote commands get to the mrf250 no matter where I am pointing the 950, however sometimes they just dont seem to get to it (no light on the mrf250) and there does not seem to be any rhyme or reason as to why. Its as if the 950 isnt sending anything. When this happens it seems to happen for a few seconds and is then OK. I'm talking about commands like a press on the up or down button, not a macro. Is this normal or should I be getting 100% success ? My room is not large and I've never noticed any interference going on.

Are you in NY? May be an issue with you needing a narrow band unit. You might be getting interference.

Is the MX-950 working all the time when you are more that 8 ft away? I have had that problem alot. I remove the antenna and it always works.

I'm in Colorado HiDef. I'll try the antenna removal trick, thanks J.Todd.

Yes before the mrf350 came out, the antenna was removed right out of the box for the 250 and 300.