lucy24 - 7:39 pm on Sep 8, 2012 (gmt 0)

Out of curiosity... what happens if you don't change the background-position directive? I wouldn't be surprised to find webkit isn't really getting it wrong: all the other browsers are. See, you've told it to flip the directionality of all right/left elements. So if you say that something is to be positioned right, and then add a <dir = "rtl"> layer, then it stands to reason that your right-aligned element should instead be left-aligned.

Swiping an idea from alt131 here... It might work better if you keyed your CSS to the direction attribute.

body[dir=ltr] {one version of your background here}
body[dir=rtl] {other version of your background here}

The folks at w3c [w3.org] go on for quite a while about directionality. There may even be something about backgrounds, but the chapter gives me a headache so I can't say for sure.