I'm getting the same issue, but as I've been following not just the sage advice of cscgal, but also the other gurus in this thread, the links still work: however my links show up as
http://www.mobileforces.org/forums/f13-.html
as my tempalte is of the following structure
<img class="inlineimg" src="$stylevar[imgdir_statusicon]/subforum_$forum[statusicon].gif" alt="" /> <a href="[b]f$forum[forumid]-[/b]$forum[url].html">$forum[title]</a>
and my .htaccess line in reference is as follows:
RewriteRule ^t([0-9]+)-(.*).html$ showthread.php?t=$1 [L]
I don't know why this is happening, as the code definitely seems to be processing properly in all other cases.
I hope there is a solution, but for this structure of link, the links still work, they are just not showing the formatted title in the link name...