Is the procedure for changing Login Banner in webmail different on multi-server setup and single server setup?

The login banner in the multi-server setup disappeared around 2-3 weeks after the upgrade to Zimbra 6.0.8.

I change the logos in /opt/zimbra/jetty/webapps/zimbra/skins/_base/logos
AppBanner.png and LoginBanner.png.

In a single server install the new logo will appear immediately after changing.

Now, in multi server install the logo does not appear at all. It used to appear.

Thanks in advance.