A dotted white line appears between each parts of the border when this border is drawn by border-image and when we rotate the element with the "transform" property.

You can see also the test web page directly at the given URL...

According to my tests, it's not related to the "transform" property: the same border is drawn without transform, by just increasing border-width. It seems to affect both repeat and round border type but not stretch (I'm using the latest linux x86_64 nightly build)

Could you file a separate bug about that? I think this is probably a duplicate of the generic bug about seams when things are transformed as a result of how we do anti-aliasing.

@David: ok, bug created : 455398

Confirmed on Windows with the latest nightly. Just to clear up the fact it's not Linux only...

Oh, and selecting the "New!" text makes it move around. Is this a known problem, or should I file it?

This bug happens even without transforms for particular combinations of top/left/width/height. I've seen it with particular fractional values of TLWH. I'll attach a testcase. Webkit has the same bug on transforms, but not without. #516793, #455398 look like dups.