VMware certificate templates

[AimarPL]

I'm trying to create new certificate templates for vcenter 5.5 on enterprise PKI running on WS2003 SP2. Following this KB: VMware KB: Creating a Microsoft Certificate Authority Template for SSL certificate creation in vSphe... I'm getting stuck at these steps:

1. In the Duplicate Template window, select Windows Server 2003 Enterprise for backward compatibility.
   
   Note: If you have an encryption level higher than SHA1, select Windows Server 2008 Enterprise.
   
   
2. Click the General tab.
3. In the Template display name field, enter VMware Certificate as the name of the new template.
4. Click the Extensions tab.
5. Select Key Usage and click Edit.
6. Select the Signature is proof of origin (nonrepudiation) option.
7. Select the Allow encryption of user data option.

As it seems, "Signature is proof of origin" option is greyed out and I can't use it. Request handling tab / Purpose option is set to "Signature and encryption".

Does anybody knows a solution for this issue?

Thanks in advance!

[tonto_22]

Do you have sufficient elevated privileges to modify Cert Templates? (i.e Domain Admin)

[AimarPL]

Of course, I am a member of domain and organization admins.

I was able to duplicate and edit this template, but this option is just grayed out.