Acer 5920 - sound drops out when piped to home theater

[Bartender]

Our Acer 5920 laptop runs a 1.5 Ghz Core2Duo, but onboard Intel video and audio.

Using VLC, I can watch a DVD or a movie ripped in Handbrake at the High Profile setting and it's perfectly acceptable. A little bit of trouble sometimes in action scenes.

The Acer has one of those headphone jacks that performs double-duty as an optical SPDIF output. If I leave the video on the laptop screen and pipe the sound to our home theater amp I get 5.1 sound, with either no audio dropouts at all or very few.

If I send audio to the home theater amp AND send video to the 32" LCD TV, we get lots of audio dropouts, litte blips of silence every 20 to 30 seconds.

Do you think that's because the Intel chipsets just don't have enough processing power? The CPU is running at about 20%, but I'm guessing that the video chipset is maxxed out and maybe that's causing audio problems as VLC tries to keep it synchronized?

I'm an amateur at this HTPC stuff so any thoughts would be appreciated.

[Bartender]

So my long-suffering wife gets home and I set up the whole thing again to show her how the sound drops out when the laptop is connected to the 32" LCD TV and the home theater amp. I can't MAKE it drop out. Even though there were some video glitches here and there, the sound held on throughout.

I thought, OK, I'll fix you, and connected an external USB 2.0 HDD dock. Plugged in a HDD with some Handbrake rips on it. So now the poor old laptop is pushing video to the TV and audio to the amp, and it's trying to process a Handbrake rip coming in across the USB interface. I still couldn't get the sound to misbehave!

Maybe there was a little piece of dirt on the optical SPDIF cable tip the first time? Or I didn't have it plugged in to the laptop all the way?