It looks to me like there's some weird issue with the fonts loaded, and editable text is being rendered through a different route than the non-editable text. The non-editable text looks to have font corruption or similar, with an off-by-one-error, perhaps on code points or similar. I reckon it's only happening when JS kicks in to augment the page though, based on eirk's description of it looking OK until JS kicks in after the page is finished loading.