I'm not sure what's going on with your OTA, but the Voom PQ has been poor for the last month or so. Voom went to new encoders that were supposed to improve things but so far all it's done is to cause a degredation in PQ both Sd and HD. I walked into my local Fry's store the other night and they were playing a feed of Discovery HD from D. I forgot how good HD was supposed to look until I saw the picture at Fry's. Voom PQ just sucks right now. It has been well over a month since we have been told "Voom is working on it." BS! I'm sick of it. I'm giving them 1 more month to fix the PQ and if it's not fixed I'm gone. Recently I've had friends ask me if they should sign up with Voom. Right now I will not recommend Voom to them. I've told them I'd let them know if the Voom PQ ever improves. But for now they need to stay away from Voom. D and E don't have enough HD for me to switch to them. If I end up leaving Voom, I'll put my HD television in storage until HD grows up. In the meantime I'll reactivate D on my SD 32" and actually enjoy TV again without having to worry about the PQ all the time. I'm just getting so frustrated with Voom's PQ and I'm about ready to dump HD for now.
What you are seeing is what a lot of us are seeing. Is it going to improve? I seriously doubt it anytime soon.