Sometimes, the installation of packages out of Sourcery stops right at the beginning. The reason can't be seen right on the desk, instead I found it in the Sourcery protocols menu. The MD5 checksum was wrong.
A similar problem might be this:
viewtopic.php?f=16&t=7700
There it said, one could use the extra command "--no-md5". Where do I have to write that to try and install dolphin for example without the MD5 check?