Created attachment 11922 [details]
Setting the viewBox="" attribute on the <svg> also results in funny drawing bugs. Play around with it :-)
The viewBox bugs are known. I just filed bug 11907 to track those.
I assume the text just isn't invalidating here after changing the transform. It looks like SVGTextElement::updateLocalTransform is supposed to do just that though. So possibly the layout is not causing the proper repaint to occur.
Fixed by bug 11984.
*** This bug has been marked as a duplicate of 11984 ***