I had obtained a similar error on my dev machine CentOS 6.4 with Puppet 3.4.3. Reinstalling Puppet again on my dev machine did not help.
I had noticed that the /tmp directory permissions were changed somehow in my dev machine. I had to fix it to get puppet agent working again.
Expected :
drwxrwxrwt 27 root root 12288 Jul 18 15:25 /tmp/
The Fix :
sudo -i
chown -R root:root /tmp
chmod 1777 /tmp
Note: when I obtained this puppet error, I also obtained another while rebooting my VM.
There is a problem with the configuration server /usr/libexec/gconf-sanity-check-2-exited with status 256
Fixing the permission/ownership rights on /tmp directory fixed both errors for me.