[bd]

Did you already try to update GPU driver?

I had really bad crashes (high pitch noise, bright white flash, driver killed) on Firefox 4 and Chrome 7 when they started to use HW acceleration and problems went away after the update.

Though this was on Windows 7, no idea about OSX.

[nkassis]

No luck on that, I checked and there was in fact a graphics update but that didn't affect the behavior. My next step is to try to figure out what is causing it to make a bug report.