HD Recordings are inconsistent. Some great. Some Awful. How come?

[dale_ander]

I've had my HTPC a little over 2 years now and it's been working great up until I "upgraded" to HD.

My hardware is currently:
Pentium 4 2.8GHz Northwood CPU (Hyperthreading, not dual core)
Pioneer DVR-A07 DVD/CD
ATI 9600 Radeon Pro 128MB Video card
Intel D856Perll Motherboard
1GB RAM
2 DVICO FusionHDTV5 RT Lite HD Tuners

I'm using SageTV 5.0.4.92 on a Windows XP Home OS
I upgraded my ATI drivers to Version 6.14.0010
DirectX Version 9.0c
Java 1.5.0_06

I installed PowerDVD7 in order to use its MPEG2 Video Decoder (took some searching on this forum to figure out how to do that thank you)

I'm using one of the AC3 Decoders that came with the Fusion software as my MPEG2 Audio Decoder. It's the best of what all I've tried so far. I still am not getting true 5.1 sound from my recordings so I'm not done fooling with this aspect of things yet but this isn't the problem I'd really like to get help on - but I'd take it! :-) FYI I'm using the optical out on the mother board and connecting it directly to my surround sound receiver.

Last, but not least, I'm using an antenna that was already in my attic for SD signals as my source for HD. (It has a signal booster that I purchased from Radio shack a year or so ago attached to it and I just left it there since I needed it for some UHF channels before.) I've got it pointed just right based on what I read on www.antennaweb.org and it sure seems like I'm getting 86% to 100% percent signal strength according to the Fusion software on all the HD channels in my area.

The problem I'd like help with is understanding how to fix my recording issues. The same channel can be recorded great on some nights and not on other nights. The recordings, when they're good, play back perfectly on my system now. The recordings, when they're bad, pixelate, stop, start, and have garbled audio. Very much like the reception is bad. I've yet to figure out any kind of pattern other than if a show doesn't record well once, it tends never to record well. As if the reception problems, if it has anything to do with reception, only occur on certain days, but usually the same days. It's very weird and very disappointing.

Before this I had two Hauppauge tuners in the system and SageTV 2.2 and it worked solidly for over two years.

I don't know if I need a new antenna or need to put my antenna outside - which I would prefer not to do.

I don't know if different HD tuners would be better than the Fusion tuners I just purchased.

I don't know if it's related to my processor speed, or lack there of, or my graphics card.

It just seems weird that some recordings can be played back perfectly and others cannot. Last night two recordings were going on at the same time and both came out perfect - even though I watched one while it was being recorded.

Any suggestions on what to try to fix things so my recordings are made and/or play back correctly would sure be appreciated.

[dale_ander]

I neglected to say that my HDTV, a new Mitsubishi DLP, is connected to the same antenna source as my two Fusion HD tuners and it never has a problem with reception.

Also, tonight's recordings all came out fine so my theory of the bad recordings being tied to a specific time, or even channel, seems out the window.

Sure wish I knew what I could do to get good recordings consistently. It's no fun having no choice but to watch commercials in order to be sure I get to watch some of my favorite shows.