I just overcame a tough little problem while branding a SharePoint 2010 site. I was trying to override the s4-title class in my themeable class but it just wouldn’t work. SharePoint Designer thought it was OK, my css class was loading last, ond IE Developer tools showed it as the active background image. Still no dice.
As is often the case when you’re overriding a class, the parent styles are in effect until overridden. I just couldn’t figure out what – the standard style didn’t show a background image. As it turns out, one was in fact declared in corev4.css (the standard set of classes). It didn’t show because it was positioned way above the page.
background:url("/_layouts/images/bgximg.png") repeat-x -0px -1023px;
I’m not sure why they do this (I suspect that it has to do with the theming engine), but my background was inheriting it. Once I added
to my overridden class, my background appeared just fine.
Hope this helps someone.