JonW747, I was not threatening you in any way; just cautioning how you might treat some people in here (Custom Installer's Lounge). I was trying to help you, if I missed something in your post, I appologize. I was merely reacting to the device you had originally mentioned, being the DTV receiver. Those receivers are notorious for having IR overload problems. As far as the Rich_Guy comment, I'm trying to warn of some negative comments and feelings he so plentifully expresses on this site. I personally feel that URC makes some great products, and do not feel they deserve all the negativity surrounding them right now.
The RFX-150 that comes with the MRF300 is a wide band RF receiver, it picks up from about 350-500MHz. So if the light is blinking on the antenna but not the MRF, maybe something is interfering with the signal. It could be a bad MRF, I personally haven't had one yet, but if you feel it is have your dealer replace it and you'll know soon enough.
On one other note, please don't bring up the "I'm an engineer" phrase, nothing against you or engineers in general, but we see that way too often here (I'm not trying to start anything, just friendly advice).