Don't use it.If you look at the demo site, you'll notice the page doesn't have a doctype, meaning the browser is forced into quirks mode. If you try adding a doctype, it'll mess up the layout completely.
I'm not going to gripe because hazelma provided this for free, but you might want to avoid the carousel component outlined. I too ran into the doctype issue, where if my html document had a doctype, the carousel was not functional.
It's a shame, because otherwise it seems like a great component that extjs needs. Oh well, tanstaafl.