I have this Editor Styles problem too.
I create my own css file and used control and click to select additional styles you I want in my editor, but all I see is the "Red Title" style.
In the .js file the StylesXmlPath is:
FCKConfig.StylesXmlPath = '../custom/editor_omschrStyles3.xml';
I also uploaded this xml file to the server.
I just can't make this work.
Can you please help me with this?