I have removed these lines below from the entries.tpl out of the /templates/default/ -folder:
{if $entry.has_trackbacks}
{if $use_popups}
| <a href="{$entry.link_popup_trackbacks}" onclick="window.open(this.href, 'comments', 'width=480,height=480,scrollbars=yes'); return false;">
{$entry.label_trackbacks} ({$entry.trackbacks})</a>
{else}
| <a href="{$entry.link}#trackbacks">{$entry.label_trackbacks} ({$entry.trackbacks})</a>
{/if}
{/if}
{if $entry.is_entry_owner and not $is_preview}
| <a href="{$entry.link_edit}">{$CONST.EDIT_ENTRY}</a>
{/if}
{$entry.add_footer}
</div>
</div>
<!--
<rdf:RDF xmlns:rdf="
http://www.w3.org/1999/02/22-rdf-syntax-ns#"
xmlns:trackback="
http://madskills.com/public/xml/rss/module/trackback/"
xmlns:dc="
http://purl.org/dc/elements/1.1/">
<rdf:Description
rdf:about="{$entry.link_rdf}"
trackback:ping="{$entry.link_trackback}"
dc:title="{$entry.title}"
dc:identifier="{$entry.rdf_ident}" />
</rdf:RDF>
-->
{$entry.plugin_display_dat}
{if $is_single_entry and not $use_popups and not $is_preview}
{if $CONST.DATA_UNSUBSCRIBED}
<br /><div class="serendipity_center serendipity_msg_notice">{$CONST.DATA_UNSUBSCRIBED|@sprintf:$CONST.UNSUBSCRIBE_OK}</div><br />
{/if}
{if $CONST.DATA_TRACKBACK_DELETED}
<br /><div class="serendipity_center serendipity_msg_notice">{$CONST.DATA_TRACKBACK_DELETED|@sprintf:$CONST.TRACKBACK_DELETED}</div><br />
{/if}
{if $CONST.DATA_TRACKBACK_APPROVED}
<br /><div class="serendipity_center serendipity_msg_notice">{$CONST.DATA_TRACKBACK_APPROVED|@sprintf:$CONST.TRACKBACK_APPROVED}</div><br />
{/if}
{if $CONST.DATA_COMMENT_DELETED}
<br /><div class="serendipity_center serendipity_msg_notice">{$CONST.DATA_COMMENT_DELETED|@sprintf:$CONST.COMMENT_DELETED}</div><br />
{/if}
{if $CONST.DATA_COMMENT_APPROVED}
<br /><div class="serendipity_center serendipity_msg_notice">{$CONST.DATA_COMMENT_APPROVED|@sprintf:$CONST.COMMENT_APPROVED}</div><br />
{/if}
<div class="serendipity_comments">
<br />
<a id="trackbacks"></a>
<div class="serendipity_commentsTitle">{$CONST.TRACKBACKS}</div>
<div class="serendipity_center">
<a rel="nofollow" style="font-weight: normal" href="{$entry.link_trackback}" onclick="alert('{$CONST.TRACKBACK_SPECIFIC_ON_CLICK|@escape:htmlall}'); return false;" title="{$CONST.TRACKBACK_SPECIFIC_ON_CLICK|@escape}">{$CONST.TRACKBACK_SPECIFIC}</a>
</div>
<br />
{serendipity_printTrackbacks entry=$entry.id}
</div>
{/if}
and it worked quite well.