IPB 4.0 uses a new retarded system where custom.css takes priority over all css files. This includes Admin CSS files. i found it...the trick is on: set as members theme...so you don't even have to make it defautl, seems that "default" option changes the ACP too. :) Yes, I know. Any changes made to the custom.css with div-styling that are used in ACP as well are changed. This includes the body-tag, buttons, and others. Custom.css takes priority over every css file. When adding a new theme as default, it is by default in the admin panel too. You can change it back to the actual default one though by clicking on "Signed in as..." and "Change Theme >". The style you used for the front side, is used for the admin panel too. Well now i read this, you are right! the custom.css is the problem