Have you tried another reputable h.264 codec, like CoreAVC which is reported to be the fastest HD decoder you can get.
I would also suggest downloading the trial of CoreAVC and setting this as the H.264 decoder. I have not been able to get ffdshow to play HD properly.
After installing CoreAVC and using this as the HD decoder, I have had smooth HD playback ever since. And since the trial doesn't cost a thing, it can't hurt to try it out.
I have never seen a HD broadcast in Mpeg-2, they are usually Mpeg-4/H.264.
Vista used to go in hybernation easy on my system (everything powered down), but since one of these windows updates a few months ago, that possibility has gone, I have no idea how that happened and why that has changed. Since then I just power it off and works ok for me.
You should go over to the Greenbutton forum, there are lots of users where standby\hibernate will not work, personally think it hardware related, have seen one of the nvidia components blamed in some cases and i had to revert to a prior driver because of issues with graphics on resume, took a while to go into standby as well (about a minute), so i knew something was not right straight away.
Some things to check, in regards to your new problem:I tried it and it works again, but now i have ro find a way that the remote responds to the pc button to get it out of hybernation.
But at least it powers down and when powerbutton is pushed it turns on quickly and mediaportal is available immediately.
Not sure if this on topic...:sorry:
lots