Edit URL doesn't work!

I want to write an article about fonts. The URL should be http://www.pumpkinzfreak.com/deleting-font/

I want to edit the URL to http://www.pumpkinzfreak.com/deleting-fonts/ but when I press OK the URL doesn’t change, seems like there’s a problem with jquery. When I try to reload or open another page, it says “webpage not found”, and take about 40 minutes to back to normal.

Is this bug or something? It drivers me mad! 🙁