Main menu overlaid on "Add Item" in K2

I recently encountered a problem in the Finance Business template, which has been resolved by support staff at Gavick, and I thought I would share the solution with other Gavick members.
If you login from the frontend, with K2 installed, and select the "Add a new item" option, the Main Menu appears superimposed on top of the popup K2 "Add Item" window. This can be resolved by adding the following code to the overide.css file through the Template Manager in the backend. Also make sure that the CSS Overide option is also enabled under the DEV MODE tab.

#sbox-window {z-index: 100001 !important}
#sbox-content {z-index: 100005 !important}

Thanks to Gavick for persevering with this.

It didn't work with me. Can you send here working overide.css

You need to remember to enable override.css in template options, please check this setting.

This is my override.css file:

/*
#------------------------------------------------------------------------
# Finance Business - #6 2011 template (for Joomla 1.5)
#
# Copyright (C) 2007-2010 Gavick.com. All Rights Reserved.
# License: Copyrighted Commercial Software
# Website: http://www.gavick.com
# Support: [email protected]
#------------------------------------------------------------------------
# Based on T3 Framework
#------------------------------------------------------------------------
# Copyright (C) 2004-2009 J.O.O.M Solutions Co., Ltd. All Rights Reserved.
# @license - GNU/GPL, http://www.gnu.org/copyleft/gpl.html
# Author: J.O.O.M Solutions Co., Ltd
# Websites: http://www.joomlart.com - http://www.joomlancers.com
#------------------------------------------------------------------------
*/
#sbox-window {z-index: 100001 !important}
#sbox-content {z-index: 100005 !important}

and this is my options:

I don't know what to do. Thank You

Please log in to your backend, go to template settings and enable override css option in template settings.