I'm kind of amused by how broken the baby emoticon is from the conflicting syntax:

<img src="img/smilies/baby.gif" align=absmiddle border=0 alt="~<img src="img/smilies/dramatic.gif" align=absmiddle border=0 alt=":o" title=":o">" title="~<img src="img/smilies/dramatic.gif" align=absmiddle border=0 alt=":o" title=":o">">

instead of just

<img src="img/smilies/baby.gif" align=absmiddle border=0 alt=":baby:" title="~:o">

And that would simply produce a .

I'd postulate that changing the order of those two smilies in file so that the baby emoticon syntax is fed first through regex replacement would fix it or it could just be changed to :baby:. I think the other 3 are choking on < and > being treated as potential HTML tags and would need new syntax entirely like
:mad:
:shiftleft:
:shiftright:
:darn:

HOWEVER in looking at that, I'm seeing some other markup errors with the page for:

Post Preview's post

<table cellspacing="0" class="c1" id=>

(id= should have "" and it won't show error anymore) and the footer's first table is missing both <tr> and <td> in the first table, and the second table has no row, and doesn't close the <td> either, so we're broken in strict mode. Also noticed that the RHDN submission database has "list"/"li" BBCode for (<ul>/<li>) (example) that has not been implemented here at the time of posting. I'll start a new thread if I run into more little things.