TV Guide Channel Pixelated on 512, Clear on 722k

[Nominal]

Scratching my head on this one. The TV Guide Channel (117) on my SD set fed by a 512 is pixelated and garbled, but the same channel on my HD set fed by a 722k is just fine. I ordinarily wouldn't care as I never watch that channel, but my mother likes to and she brought it to my attention. It looks and sounds like what happens when there's rain fade or a dish obstruction of some kind, but like I said the same channel at the same time on a 722k is clear as a bell. Anyone else with a SD receiver having this problem

EDIT: Did a hard reboot of the 512 to no avail, but also did a Check Switch/Test and that seems to have cleared it up for now.
EDIT 2: Spoke too soon, the picture and sound have started to break up again.

 

[TheKrell]

Weird. Are you on mixed arc, e.g. 61.5/72/110/119? I am wondering whether the two receivers are actually tuned to the same or different channels.

 

[Nominal]

Weird. Are you on mixed arc, e.g. 61.5/72/110/119? I am wondering whether the two receivers are actually tuned to the same or different channels.

Pure Western Arc (110/119/129) fed by a 1000.2.

 

[Nominal]

Solution?

Think I might have fixed the problem, I replaced the DPP Separator on the 512 with a spare I had around and so far, so good. Strange that a dying separator would affect just one channel though. Live and learn, I guess lol.