Must be something to do with the way IE interprets nested tags - the vB formatting tags are translated verbatim to HTML, so the last line of the post is:
<font color=“Green”><u>
<font color=“Blue”><del>
<font color=“Red”>red text with blue strikethrough, underlined in green</font>
</del></font>
</u></font>
(line breaks inserted here for clarity)
I’m pretty sure Firefox is rendering it the way it’s supposed to be done.
IE on this machine displays it as Puzzler described - I thought for a moment it might be that the server is dishing up a different bit of code depending on the browser that’s asking for it - but no, it’s the same in either case (or at least that particular line is - it might be something else impacting on it).