Apple has made its Mac OS X 10.5.3 update available. Among the bug fixes:

“Addresses an issue with stuttering video and audio playback in certain USB devices.”

Also interesting, given that some issues may have been related to wireless issues: “Improves 802.1X behavior and reliability.”

About the Mac OS X 10.5.3 Update [Knowledge Base HT1141 at Apple Support]

Thanks to John for the tip. (I hear shouts of joy from various people as that Software Update dialog pops up…)

This would appear to address at least some of the audio performance complaints with 10.5.2. Those of you who have been having issues who were unable to downgrade, let us know as you test if it seems to make your problems go away.

Because operating systems are complex, however, it was unclear whether this was the only issue with 10.5.x and audio, so we’ll also be watching for more comprehensive testing feedback from CDM readers and music and audio product makers. (Specifically, we had gotten reports of issues with FireWire devices as well as USB, meaning this may not be the complete fix we had hoped for. But Apple software update release notes are notorious for being vague and incomplete; as Vince notes in comments, the version number on the FireWire driver has in fact changed and there may be other changes not explicitly listed in the notes.)