Did you install Diaspora* as root? This is is absolutely not recommended, Diaspora* should be installed under a normal user.
Quote from Diaspora* installation instructions:
We frequently see people doing everything as root. If you think that's a good idea: It's not. It's the worst thing you can do! All programs will either tell you to run them as root or ask you for the password. Do not start anything as root if it's not explicitly requested by it or this guide. Just use your normal user or create an own system user for Diaspora.
https://wiki.diasporafoundation.org/Installation