I see that these are fairly old posts, but I just stumbled onto the SA8300HD issue myself. My client upgraded his cable box to HD and got the SA 8300HD box. From the moment we turned it on we started to have intermittent problems with the IR that previoiusly was flawless. Sometimes it takes the channel command right away and sometimes it takes several hits to work. (often giving a false channel number in return). Frustration!! I was using a MX-850 with a MRF-300 and suspected that the gain was too high. I tried to lower it to the lowest (then raised it to the highest), and everything inbetween. I moved the emitter around the faceplate and even pulled it off to the cabinet frame and top/bottom of the cable box. Nothing helped. I pulled out an old MRF-200 without any
ID code and set the remote to "0" (probably didn't matter because a non-programmable RF receiver like the 200 grabs any RF it can see. This approach improved the response orders of magnitudes. There were still some false hits, but dramatically improved the situation. My question is, why does this cheap box work better (could it be a very tiny IR signal out of the emitter?), but more importantly.... what can we do to make the cable boxes robust? I see references to remodulators (I'll have to read up on them and see what they cost etc. etc.), but is it a saturation problem?? It's a pretty popular box it seems, and I can't keep installing systems that don't work right. I have spent WAY too much time and the customer sure isn't happy with the results!