[mey]

I'm going to go out on a limb and assume you have an Intel or nvidia chip set in your mac. See http://code.google.com/p/chromium/issues/detail?id=159275 (which references http://code.google.com/p/chromium/issues/detail?id=137303 but we can't see)

There is a security issue in the OSX drivers for certain chipsets, and AA is broken. Google Chrome has taken the step to disable AA on these systems to prevent an exploit of the OS.

[jpxxx]

Sounds right, good sleuthing, thank you. This machine has an Intel 3000.

The stars appear properly placed, but instead of a point there's an effect-ruining translucent square around each one. The single-pixel distance lines also look wrong during transitions.

Since this mystery ends in a Radar ticket about GPU drivers, I won't hold my breath for a fix. As far as Apple is concerned, it ain't broke until Final Cut is broke.