I was validating my HTML the other day, as you do, and I found an error in the comment hyperlink at the bottom of a particular post. This post happened to have the " character in it and this was the source of the error. In the permalink, the " " were translated into & #8220; and & #8221; (ignore the spaces after the ampersands, this program keeps parsing my text into quote characters!) but in the comment hyperlink, in the title attribute, they were just displayed as " and ". Visually, on the mouse-over of the hyperlink I only saw "Comment on " rather than it including the name of the post.
More importantly, though, it's broken HTML because the character isn't properly escaped.
I tried editing the post, saving it as something else and then changing it back, in case it's encoded when it's saved. (I wrote that post when on WP 1.5.2.) That didn't work, though. It must be the rendering at runtime that's not encoding it properly.
I'm more an ASP.NET guy myself so my PHP is limited. Is there somewhere I could hack this until a new version fixes it?