Chosing a repository name written with exactly 4 chinese characters causes the repository URL to be of the form:
where each chinese character has been replaced by a dash. Trying to create a different repository with a different name, but the same number of characters (e.g. 4 in this case), results in the following message on https://bitbucket.org/repo/create:
"You already have a repository with this name."
The name of the first repository is displayed correctly in the web interface. Adding some form of repository ID the the URL would solve this problem.