That's not all that's broken: per-site CSS isn't being applied properly. You have to load a site, then click reload before the CSS is applied. Reverting to 89327 (July 27) fixes both issues.
Even though OW 5.6 is pretty stable for an Alpha, it's an Alpha build. I look forward to the Betas! Leopard is just around the corner as well which means there is hope that a STABLE WebKit will appear sometime soon. WK is still very unstable in it's current form.