Considering its been ages now, I have reinstalled Xoops, reinstalled newbb, changed theme and the merging problem still occurs. I even changed bloody host and the same thing appears.
Here is "newbb_viewtopic_flat.html", I know i have m ine set to flat.
<!-- start module contents -->
<table border="0" width="100%" cellpadding='5' align='right'>
<tr>
<td align='left'><img src='<{$xoops_url}>/modules/newbb/images/folder.gif' alt='' /> <a href='<{$xoops_url}>/modules/newbb/index.php'><{$lang_forum_index}></a><br /> <img src='<{$xoops_url}>/modules/newbb/images/folder.gif' alt='' /> <a href='<{$xoops_url}>/modules/newbb/viewforum.php?forum=<{$forum_id}>'><{$forum_name}></a>
<br /> <img src='<{$xoops_url}>/modules/newbb/images/folder.gif' alt='' /> <b><{$topic_title}></b></td><td align='right'><{$forum_post_or_register}></td>
</tr>
</table>
<br />
<!-- start topic thread -->
<table cellpadding="4" width="100%">
<tr>
<td align="left"><a id="threadtop"></a><a href="viewtopic.php?viewmode=thread&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>"><{$lang_threaded}></a> | <a href="viewtopic.php?viewmode=flat&order=<{$order_other}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>"><{$lang_order_other}></a></td>
<td align="right"><a href="viewtopic.php?viewmode=flat&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>&move=prev&topic_time=<{$topic_time}>"><{$lang_prevtopic}></a> | <a href="viewtopic.php?viewmode=flat&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>&move=next&topic_time=<{$topic_time}>"><{$lang_nexttopic}></a> | <a href="#threadbottom"><{$lang_bottom}></a></td>
</tr>
</table>
<table cellspacing="1" class="outer">
<tr align='left'>
<th width='20%'><{$lang_poster}></th>
<th><{$lang_thread}></th>
</tr>
<{foreach item=topic_post from=$topic_posts}>
<{include file="db:newbb_thread.html" topic_post=$topic_post}>
<{/foreach}>
<tr class="foot" align="left">
<td colspan="2" align="left"><{$forum_page_nav}> </td>
</tr>
</table>
<table cellpadding="4" width="100%">
<tr>
<td align="left"><a id="threadbottom"></a><a href="viewtopic.php?viewmode=thread&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>"><{$lang_threaded}></a> | <a href="viewtopic.php?viewmode=flat&order=<{$order_other}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>"><{$lang_order_other}></a></td>
<td align="right"><a href="viewtopic.php?viewmode=flat&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>&move=prev&topic_time=<{$topic_time}>"><{$lang_prevtopic}></a> | <a href="viewtopic.php?viewmode=flat&order=<{$order_current}>&topic_id=<{$topic_id}>&forum=<{$forum_id}>&move=next&topic_time=<{$topic_time}>"><{$lang_nexttopic}></a> | <a href="#threadtop"><{$lang_top}></a></td>
</tr>
</table>
<p align="left">
<!-- end topic thread -->
<br />
<table cellspacing="0" class="outer" width="100%">
<tr class='foot'>
<td align='left'> <{$forum_post_or_register}></td>
<td align='right'><{$forum_jumpbox}> </td>
</tr>
<tr class='foot' valign="bottom">
<{if $viewer_is_admin == true}>
<td colspan='2' align='left'> <{$topic_lock_image}> <{$topic_move_image}> <{$topic_delete_image}> <{$topic_sticky_image}> </td>
<{else}>
<td colspan='2'> </td>
<{/if}>
</tr>
</table>
<{include file='db:system_notification_select.html'}>
<!-- end module contents -->