the coding looks fine although the line with:
HTML Code:
<td class="alt2" width="176" nowrap="nowrap">$forum[lastpostinfo]</td>
doesn't have the width or nowrap tags in the default template. You could try taking those out to see if it works.
Other thoughts... it could be the title rows (with Icon / Forum / Last Post / Threads / Posts) that's messing everything up.
Or you could check the forumhome_lastpostby template.
*shrugs*