The issue is that the user in question is using the utf-8 character set and this website isn't setting the charset attribute to utf-8. Since this is an English message forum, that is probably fine. My company has some internal web based client server apps that need to support utf-8 since we are a worldwide company. The real pain in the butt is trying to determine what character set some user is cutting and pasting so that it can be correctly saved in utf-8!
In IE you can left click your mouse, click on Encoding and then select utf-8 to see the "funny" characters.