Today, I perceived my gnome applications have a long delay start. A wiki google reveal me the problem.
My hostname, in the /etc/hosts file, was not associated with 127.0.0.1 address. I add the following line:
127.0.0.1 pdclab-09.ece.uprm.edu pdclab-09
and the problem was resolved.
https://bugs.launchpad.net/ubuntu/+source/gnome-system-tools/+bug/12852 as a matter of fact my problem happened in a FC7 machine.