Don't know about other's experience but I've never heard of any significant incompatibility with AMD chips. I've run just about any kind of software you can name for years on AMD without a single CPU related compatibility problem. The 64 bit systems are still pretty new technology so I'd expect some minor glitches. I assume you have the latest drivers for the sound card. Have you tried running without any background applications? Is there an onboard sound system on the MB that might be acting up? "A Quicktime file's sound will lag the video..." Only QT or other video formats as well? Most of the symptoms sound like some kind of buffering issue though I don't know what might be causing it.

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