There is an annoying problem with posts containing html code samples, or perhaps anything with a less-than sign.
For example, it quite possible to make a post containing the text [SCRIPT] (with less-than/greater-than brackets). In the html view, the less-than sign would be correctly escaped as "& lt;".
However, when the post is edited, the editor loads the escaped less-than sign as a plain less-than sign in html view.
So every time a post containing less-than signs is edited, a whole lot of manual editing in html view is required.