Comment 8 for bug 1020048

I can confirm the bug too.
My solution:
- Look into the file /etc/cups/cupsd.conf
- The following entry is listed: Listen 127.0.0.1:631
- Edit this entry from 127.0.0.1 -> localhost
- Add this line: Listen /var/run/cups/cups.sock
- Restart cups (ubuntu): restart cups

cat /etc/cups/cupsd.conf
...
...
...
# Only listen for connections from the local machine.
Listen localhost:631
Listen /var/run/cups/cups.sock
...
...
...