XHTML Entities
I had
a similar problem the other day when I unwittingly threw an ampersand in a link's querystring and proceeded to blow up my rss feed. Nice work.
Anyway, I've only tested this on my exceedingly simple html posts and I think it might need a lock on the hashtable in the ctor. In other words, if you want to avoid retyping all the html 4.01 entities over again, you
can grab this. Known problem: if you use single-quotes instead of double-quotes on your html attributes (which is legal--but I don't as a rule), it's going to go haywire and replace them on you. Remove it from the character-level encoding (apos) and you'll be fine, just play nice and use ' where necessary on your own.