Parse Templete Problems in my Plugin

[Benumbed]

    <plugin active="1" executionorder="1">
      <title>Set Widths (Parse Templates)</title>
      <hookname>parse_templates</hookname>
      <phpcode>
        <![CDATA[
				$find = '<td class=\"alt2\"><img src';
				$replace = '<td class=\"alt2\" width=\"$vboptions[\'setwidths_forumhome_icon\']\"><img src';
				$vbulletin->templatecache['forumhome_forumbit_level2_post'] = str_replace($find,$replace,$vbulletin->templatecache['forumhome_forumbit_level2_post']);
			]]>
      </phpcode>
    </plugin>

The resulst will be "width=" as if its not parsing $vboptions. It will work fine if I manually change it instead of the plugin, why wont the plugin do it?