Hola,
Copia y pega lo siguiente en tu theme.php:
// HTML template for the category list
$template_cat_list = <<<EOT
<!-- BEGIN header -->
<tr>
<td class="tableh1" align="left"><b>{CATEGORY}</b></td>
</tr>
<tr>
<td>
<div class="categories">
<!-- END header -->
<!-- BEGIN catrow_noalb -->
<div class="catcell">
{CAT_THUMB}<br /><span class="catlink">{CAT_TITLE}</span><br />{CAT_DESC}<br />{PIC_COUNT} photos in {ALB_COUNT} albums
</div>
<!-- END catrow_noalb -->
<!-- BEGIN catrow -->
<div class="catcell">
<div style="float: left; width: 24%; text-align: center;">
{CAT_THUMB}
</div>
<div style="float: right; width: 74%;">
<span class="catlink">{CAT_TITLE}</span><br /><span class="thumb_caption">{CAT_DESC}<br />{PIC_COUNT} wallpapers in {ALB_COUNT} albums</span></div>
<div style="clear: both;"></div>
</div>
<!-- END catrow -->
<!-- BEGIN footer -->
</div>
</td>
</tr>
<tr>
<td colspan="3" class="tableh1" align="center"><span class="statlink">{STATISTICS}</span></td>
</tr>
<!-- END footer -->
<!-- BEGIN spacer -->
<img src="images/spacer.gif" width="1" height="7" border="" alt="" /><br />
<!-- END spacer -->
EOT;
function theme_display_film_strip(&$thumb_list, $nbThumb, $album_name, $aid, $cat, $pos, $sort_options, $mode = 'thumb')
{
global $CONFIG, $THEME_DIR;
global $template_film_strip, $lang_film_strip;
static $template = '';
static $thumb_cell = '';
static $empty_cell = '';
static $spacer = '';
if ((!$template)) {
$template = $template_film_strip;
$thumb_cell = template_extract_block($template, 'thumb_cell');
$empty_cell = template_extract_block($template, 'empty_cell');
}
$cat_link = is_numeric($aid) ? '' : '&cat=' . $cat;
$thumbcols = $CONFIG['thumbcols'];
$cell_width = ceil(100 / $CONFIG['max_film_strip_items']) . '%';
$i = 0;
$thumb_strip = '';
foreach($thumb_list as $thumb) {
$new_size = 65;
preg_match('/(?<=width=")[0-9]*/',$thumb['image'],$matches,PREG_OFFSET_CAPTURE);
$srcWidth=$matches[0][0];
preg_match('/(?<=height=")[0-9]*/',$thumb['image'],$matches,PREG_OFFSET_CAPTURE);
$srcHeight=$matches[0][0];
$ratio = max($srcWidth, $srcHeight) / $new_size;
$ratio = max($ratio, 1.0);
$destWidth = (int)($srcWidth / $ratio);
$destHeight = (int)($srcHeight / $ratio);
$thumb['image']=preg_replace('/width="[^"]*"/','width="'.$destWidth.'"',$thumb['image']);
$thumb['image']=preg_replace('/height="[^"]*"/','height="'.$destHeight.'"',$thumb['image']);
$i++;
if ($mode == 'thumb') {
$params = array('{CELL_WIDTH}' => $cell_width,
'{LINK_TGT}' => "displayimage.php?album=$aid$cat_link&pos={$thumb['pos']}",
'{THUMB}' => $thumb['image'],
'{CAPTION}' => $thumb['caption'],
'{ADMIN_MENU}' => ''
);
} else {
$params = array('{CELL_WIDTH}' => $cell_width,
'{LINK_TGT}' => "index.php?cat={$thumb['cat']}",
'{THUMB}' => $thumb['image'],
'{CAPTION}' => '',
'{ADMIN_MENU}' => ''
);
}
$thumb_strip .= template_eval($thumb_cell, $params);
}
if (defined('THEME_HAS_FILM_STRIP_GRAPHICS')) {
$tile1 = $THEME_DIR . 'images/tile1.gif';
$tile2 = $THEME_DIR . 'images/tile2.gif';
} elseif (defined('THEME_HAS_FILM_STRIP_GRAPHIC')) {
$tile1=$tile2=$THEME_DIR . 'images/tile.gif';
} else {
$tile1=$tile2= 'images/tile.gif';
}
$params = array('{THUMB_STRIP}' => $thumb_strip,
'{COLS}' => $i,
'{TILE1}' => $tile1,
'{TILE2}' => $tile2,
);
ob_start();
starttable($CONFIG['picture_table_width']);
echo template_eval($template, $params);
endtable();
$film_strip = ob_get_contents();
ob_end_clean();
return $film_strip;
}
?>
Recorda volver a realizar las modificaciones si ya habias modificado esa porcion de codigo. En este momento, además, has agregado algunas nuevas llamadas al style.css, entonces agregale lo siguiente:
.catcell {
float: left;
width: 32%;
text-align: left;
margin: 5px auto;
padding-left: 5px;
}
Además, vas anotar que si colocas esto y tenes una categoria vacia, te va a arrojar un error. Asi que, no tengas categorias vacias

Saludos,