Help, my tital don't want to change, the preview page don't show the same result as the edit page

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Firstly I create a site and they ask for a name

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I choose this one and the site tagline

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So when I come the the preview page it look like this (not very pretty)

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So in the edit page I changed for this.

But, the preview mode continue to show me the the not so pretty title. How to I change the title effectivly in the preview mode ?