PPA "do-core" doesn't works for Maverick amd64

jonas@jonas-desktop:~$ sudo apt-add-repository ppa:do-core/ppa
[sudo] password for jonas:
Executing: gpg --ignore-time-conflict --no-options --no-default-keyring --secret-keyring /etc/apt/secring.gpg --trustdb-name /etc/apt/trustdb.gpg --keyring /etc/apt/trusted.gpg --primary-keyring /etc/apt/trusted.gpg --keyserver keyserver.ubuntu.com --recv A5D19FDCAA6ABB440CD3464628A8205077558DD0
gpg: requesting key 77558DD0 from hkp server keyserver.ubuntu.com
gpg: key 77558DD0: public key "Launchpad PPA for GNOME Do Core Team" imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)

jonas@jonas-desktop:~$ sudo apt-get update
[...]
Err http://ppa.launchpad.net maverick/main Sources
  404 Not Found
Err http://ppa.launchpad.net maverick/main amd64 Packages
  404 Not Found
[...]
Fetched 20.3kB in 12s (1,681B/s)
W: Failed to fetch http://ppa.launchpad.net/do-core/ppa/ubuntu/dists/maverick/main/source/Sources.gz 404 Not Found

W: Failed to fetch http://ppa.launchpad.net/do-core/ppa/ubuntu/dists/maverick/main/binary-amd64/Packages.gz 404 Not Found

E: Some index files failed to download, they have been ignored, or old ones used instead.