In Portal.template.php
search:
<a class="sp_float_right" style="padding-top: 7px;" href="javascript:void(0);" onclick="sp_collapseBlock(\'', $block['id'], '\')"><img id="sp_collapse_', $block['id'], '" src="', $settings['images_url'], $block['collapsed'] ? '/expand.gif' : '/collapse.gif', '" alt="*" /></a>';
Replace with:
<a class="sp_float_right" href="javascript:void(0);" onclick="sp_collapseBlock(\'', $block['id'], '\')"><img id="sp_collapse_', $block['id'], '" src="', $settings['images_url'], $block['collapsed'] ? '/expand.gif' : '/collapse.gif', '" alt="*" /></a>';