Quick html question too...

All my pages are valid xhtml except my portfolio page because of the amount of repeated divs. I get these warnings.

Line 34, character 11:
<div id="leftport"><img src="assets/2006/thumbs/nc001.gif" ...
^Error: ID leftport already defined

Line 25, character 12:
<div id="leftport"><img src="assets/2006/thumbs/jn001.gif" ...
^ID leftport first defined here

Line 35, character 12:
<div id="rightport">Nelsco Mockups (Nov. 2005)<br />
^Error: ID rightport already defined

Line 26, character 12:
<div id="rightport">Jettison Never (Nov. 2005)<br />
^ID rightport first defined here

Line 42, character 12:
<div id="leftport"><img src="assets/2006/thumbs/bs001.gif" ...
^Error: ID leftport already defined

Line 25, character 12:
<div id="leftport"><img src="assets/2006/thumbs/jn001.gif" ...
^ID leftport first defined here

Line 43, character 12:
<div id="rightport">Browsingsafely (Nov. 2005)<br />
^Error: ID rightport already defined

Line 26, character 12:
<div id="rightport">Jettison Never (Nov. 2005)<br />
^ID rightport first defined here

Line 50, character 12:
<div id="leftport"><img src="assets/2006/thumbs/as001.gif" ...
^Error: ID leftport already defined

Line 25, character 12:
<div id="leftport"><img src="assets/2006/thumbs/jn001.gif" ...
^ID leftport first defined here

Line 51, character 12:
<div id="rightport">Astereo Promo (Nov. 2005)<br />
^Error: ID rightport already defined

Line 26, character 12:
<div id="rightport">Jettison Never (Nov. 2005)<br />
^ID rightport first defined here
Part of page html causing problem...

<div id="leftport"><img src="assets/2006/thumbs/jn001.gif" alt="JN 1" width="116" height="85" /> <img src="assets/2006/thumbs/jn002.gif" alt="JN 2" width="116" height="85" /> <img src="assets/2006/thumbs/jn003.gif" alt="JN 3" width="116" height="85" /></div>
<div id="rightport">Jettison Never (Nov. 2005)<br />
<span class="style1">Completed in a week, a mostly css design for an indie band.
<span class="style2">Valid CSS</span> / <span class="style2">Full Site Design</span><br />
<a href="#" class="style9" onclick="MyWindow=window.open('review.html','MyWindow','toolbar=no,location=no,directories=no,status=no,menubar=no,scrollbars=no,resizable=no,width=32 5,height=400'); return false;">Read Review</a> / <a href="http://www.jettisonnever.com" target="_blank">Launch
Site</a> / <a href="javascript:popup('assets/2006/full/fs001.gif',505,405);">View Screenshot</a> </span> </div>

<div style="clear:both;" ></div>

<div id="leftport"><img src="assets/2006/thumbs/nc001.gif" alt="NC Mockup" width="116" height="85" /> <img src="assets/2006/thumbs/nc002.gif" alt="Nc Mockup 2" width="116" height="85" /> <img src="assets/2006/thumbs/nc003.gif" alt="N/A" width="116" height="85" /></div>
<div id="rightport">Nelsco Mockups (Nov. 2005)<br />
<span class="style1">Logo and Design mockups. Not used.<br />
</span><span class="style2 style1">Logo</span><span class="style1"> / </span><span class="style2 style1">Design</span><br />
<span class="style1"><a href="javascript:popup('assets/2006/full/nc001.gif',505,405);">View Screenshot</a></span></div>

<div style="clear:both;" ></div>

<div id="leftport"><img src="assets/2006/thumbs/bs001.gif" alt="BS 001" width="116" height="85" /> <img src="assets/2006/thumbs/bs002.gif" alt="BS 002" width="116" height="85" /> <img src="assets/2006/thumbs/nc003.gif" alt="N/A" width="116" height="85" /></div>
<div id="rightport">Browsingsafely (Nov. 2005)<br />
<span class="style1">Completed in under a week. Requested it had the same setup as astereo.
<span class="style2">Valid XHTML &amp; CSS</span> / <span class="style2">Index &amp; Sub Pg</span><br />
<a href="http://www.browsingsafely.com" target="_blank">Launch Site</a> / <a href="javascript:popup('assets/2006/full/bs001.gif',505,405);">View Screenshot</a></span> </div>

<div style="clear:both;" ></div>

<div id="leftport"><img src="assets/2006/thumbs/as001.gif" alt="ASP 1" width="116" height="85" /> <img src="assets/2006/thumbs/as002.gif" alt="ASP 2" width="116" height="85" /> <img src="assets/2006/thumbs/as003.gif" alt="ASP 3" width="116" height="85" /></div>
<div id="rightport">Astereo Promo (Nov. 2005)<br />
<span class="style1">Promo image for astereo first birthday this January.
<span class="style2">Graphic</span> / <a href="javascript:popup('assets/2006/full/as001.gif',505,405);">View Image</a></span> </div>

<div style="clear:both;" ></div>
Any ideas?
regards