Custom Portal Logon Page

Hi,

I have been trying to replace the branding image on the portal logon page. When I recreate the logon par file and change the autheschemes.xml file and restart, as mentioned the documentation it does not take effect. My confusion is that although i have written a custom component (copy of the standard) the branding image actually seems to be supplied by another web app running on the j2ee engine, namely com.sap.security.core.admin. How do changes I deploy as a PAR effect this web app? I am running EP6 SP9 Patch 4.

Any tips woudl be appriciated. Thanks,

Simon