[Scrub]

Try this:

<if condition="$show['threadicons']">
		<td class="alt2">
            <if condition="$show['threadicon'] && $thread[preview] && !empty($thread[preview]) && $bbuserinfo[field5] != 'No'">
                <img src="$thread[threadiconpath]" alt="" border="0" onmouseover="return doPreview('$thread[preview]');" onmouseout="return nd();" />
            <else />
                <if condition="!$show['threadicon'] && $thread[preview] && !empty($thread[preview]) && $bbuserinfo[field5] != 'No'">
                    <img src="images/icons/icon1.gif" alt="" onmouseover="return doPreview('$thread[preview]');" onmouseout="return nd();" />
                <else />
                    <if condition="$show['threadicon']">
                        <img src="$thread[threadiconpath]" alt="alt="$thread[threadicontitle]"" border="0" />
                    <else />
                        <img src="images/icons/icon1.gif" alt="Post" />
                    </if>
                </if>
            </if>
        </if>

Chroder, I belive you forgot an </if> in the threadbit edit.