cairo, rasterizing text

I have some text in cairo that I want to flip vertically. I can do it with scale(1,-1) but the problem is the font face is being kerned in reverse, and so the letter glyphs are not lining up just perfect. I'm going for a web 2.0 mirrored text effect. What I want is to rasterize the text layer, copy it, and then scale it on the negative y axis. Problem is I don't know if it's possible with cairo. Any cairo wizards out there? Cheers.

Rasterise your text to a bitmap, then flip that (perhaps)?