Just run the BananaBread demo on Mac OS X 10.6 AR: Graphic issues, the screen is reverted In browser console: "[17:22:45.269] Use of getPreventDefault() is deprecated. Use defaultPrevented instead. @ https://mozorg.cdn.mozilla.net/media/js/libs/jquery-1.7.1.min.js:3 [17:22:45.555] Error: WebGL: renderbufferStorage: internalformat: invalid enum value 0x81a6 @ https://developer.cdn.mozilla.net/media/uploads/demos/a/z/azakai/3baf4ad7e600cbda06ec46efec5ec3b8/bananabread_1373485124_demo_package/bb.js:4697 [17:22:45.555] Error: WebGL: renderbufferStorage: internalformat: invalid enum value 0x1902 @ https://developer.cdn.mozilla.net/media/uploads/demos/a/z/azakai/3baf4ad7e600cbda06ec46efec5ec3b8/bananabread_1373485124_demo_package/bb.js:4697" Mac OS X 10.6 specific. Repro on FF 25.0.1, 26b6. Not repro on FF 27.0a2, 28.0a1

Don't really care about bugs on 10.6; small user base, unlikely to be running bleeding edge content. This is likely some WebGL feature that 10.6 gfx drivers handle buggily (there are a bunch). We'll hopefully stop supporting 10.6 at some point soon anyway. We can probably drop 10.6 from all the testing.

http://armenzg.blogspot.de/2013/11/re-thinking-our-mac-os-x-continuous.html says that 34% of our OS X users are on 10.6, FWIW.

IMO, this issue is unacceptable even if 10.6 is a little outdated.