Hello sugar gurus

my version is Version 5.1.0b
I am trying to bypass the sugar crm login screen as described in this post by the poster. http://www.sugarcrm.com/forums/show...2&highlight=sso
I am having a CAS provider.

But when I changed the Login php its not allowing me to go directly in to sugarcrm after authentication.
it says This copy of the SugarCRM customer relationship management program appears to have legal notices or author attributions modified or removed in violation of the GNU General Public License version 3. Please contact SugarCRM Inc. to correct this problem.

I am able to get around the checks by commenting the line $msi0="len";$msi="code";$msi1=........ in mvc_utils.php. Not sure if that is the right way but I am able to surpass the annoying message.

I am very sure that I did not changed the Logo or license statements, Its as it is as provided. They why this is happening.
Can any one tell me what the issue is?
Any pointers in this direction is wonderful.
Mark