Just a quick note that may save someone a lot of frustration. This problem was observed with an ASRock Vision 3D system but could affect other HTPC’s as well.
If you are getting single-color (probably red) “sparklies” (pinpoints of light that don’t belong) in certain scenes, or when viewing certain static images, it may NOT be a software problem. It seems that on certain systems the HDMI output may be running a little “hot” (not referring to temperature, but rather output levels) and may be overdriving the HDMI input of a connected TV. To the best of my knowledge, there is absolutely nothing you can do to fix this in software – it’s a hardware problem, perhaps a hardware defect.
But what you can try is attenuating the HDMI signal just a bit. If you have a HDMI switch (preferably an unamplified one), try making the connection through that instead of directly to the TV. In at least one case, that solved the problem. Or, if you have a very long but unamplified HDMI cable handy, you could try that (remember, any additional amplification of the signal will probably only make the problem worse!).
And if you found this article by searching on “ASRock Vision 3D”, I will just say that in my opinion, it’s not worth the price they are currently getting for it. It’s kind of a hassle to get it working under Ubuntu Linux, and although it costs about two to three times as much as, say, an Acer Asprie Revo, you don’t get two to three times the performance (in my admittedly subjective evaluation), and you might get the HDMI output issue mentioned here. Whether it works any better under Windows I wouldn’t know – even at the price they charge they don’t supply a copy of Windows, so we opted to use Ubuntu, which worked fine back when we set up the Acer Aspire Revo’s (if we were doing it today, we’d probably choose Linux Mint instead). In my personal opinion, you might be a lot happier with something else unless you are a real Linux geek and don’t mind tinkering until you can get everything working right, or perhaps if you plan to splurge for a copy of Windows — again, can’t say if that would work any better.