Hi,
in your theme.php file, copy this code
// HTML template for title row of the thumbnail view (album title + sort options)
if (!isset($template_thumb_view_title_row)) { //{THEMES}
$template_thumb_view_title_row = <<<EOT
<table width="100%" cellpadding="0" cellspacing="0">
<tr>
<td width="100%" class="statlink"><h2>{ALBUM_NAME}</h2></td>
<td><img src="images/spacer.gif" width="1" alt="" /></td>
<td class="sortorder_cell">
<!-- Remove this line to display sort options
<table cellpadding="0" cellspacing="0">
<tr>
<td class="sortorder_options">{TITLE}</td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=ta" title="{SORT_TA}"> + </a></span></td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=td" title="{SORT_TD}"> - </a></span></td>
</tr>
<tr>
<td class="sortorder_options">{NAME}</td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=na" title="{SORT_NA}"> + </a></span></td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=nd" title="{SORT_ND}"> - </a></span></td>
</tr>
<tr>
<td class="sortorder_options">{DATE}</td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=da" title="{SORT_DA}"> + </a></span></td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=dd" title="{SORT_DD}"> - </a></span></td>
</tr>
<tr>
<td class="sortorder_options">{POSITION}</td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=pa" title="{SORT_PA}"> + </a></span></td>
<td class="sortorder_options"><span class="statlink"><a href="thumbnails.php?album={AID}&page={PAGE}&sort=pd" title="{SORT_PD}"> - </a></span></td>
</tr>
</table>
remove this line to display sort options -->
</td>
</tr>
</table>
EOT;
} //{THEMES}
you can see the 2 commented lines i have added for not showing the sort options.