[Victor D]

1. Try to execute cleanup.php on your store root or clean up templates cache in admin
2. If the problem is not solved check if your into skin1/main/error_login_incorrect.tpl looks like this:

{* $Id: error_login_incorrect.tpl,v 1.35 2005/11/30 17:02:36 max Exp $ *}
{$lng.txt_login_incorrect}
<p />
{capture name=dialog}
{include file="main/login_form.tpl"}
{/capture}
{include file="dialog.tpl" title=$lng.lbl_authentication content=$smarty.capture.dialog extra='width="100%"'}

I have found there is no quota symbol in line {include file="main/login_form.tpl"}