but I would try:
<table dir=rtl class="outer" cellspacing="1">
<tr>
<td><marquee behavior="scroll" direction="right" scrolldelay="50" scrollamount="2" onMouseOver="this.stop()" onMouseOut="this.start()">
<{if $block.full_view == true}>
<table>
<tr>
<{foreach item=topic from=$block.topics}>
<td><a href="<{$xoops_url}>/modules/newbb/viewtopic.php?topic_id=<{$topic.id}>&forum=<{$topic.forum_id}>&post_id=<{$topic.post_id}>#forumpost<{$topic.post_id}>"><{$topic.title}> .:. </a>
</td>
<{/foreach}>
</tr>
</table>
<{/if}>
</marquee>
</td>
</tr>
</table>