Round Cube Error

I can log into roundcube fine. I see my folders on the left and the messages just fine, but when I double click on a message I get the following error.

Parse error: parse error, unexpected T_CONSTANT_ENCAPSED_STRING in /********/webmail/program/include/main.inc(535) : regexp code on line 1

Fatal error: Failed evaluating code: rcube_xml_command('object', 'name="mailboxlist" type="select" noSelection="moveto" maxlength="25" onchange="rcmail.command(''moveto'', this.options[this.selectedIndex].value)" class="mboxlist" /') in /********/webmail/program/include/main.inc on line 535

Thanks,

Mat