Infinite Redirect

Hi,
By mistake, i named a Blog post the same as a page. I noticed this, because the menu item, which atually took me to the page http://www.musikzentrale.net/projektwoche-2014 redirects To the post http://www.musikzentrale.net/projektwoche-2014-startet-am-26-mai/

As i realized this, i deleted the post completely, Set up the page as Menu item again. But now, this leads to redirect to http://www.musikzentrale.net/projektwoche-2014-startet-am-26-mai/, and as this One is removed, to 404.

Hope i explaned it right, any idea to Solve it is highly appreciated.

Thanks, Sebastian