In Ubuntu 6.10 (Edgy) and 7.04 (Feisty) a misconfiguration in your hosts file could be slowing GNOME applications down when they start Open /etc/hosts as root in a text editor. If you see something like this:
Change it to this:
127.0.0.1 localhost computername
Replace computername with your Ubuntu computer’s name. The bug report for this problem can be found here.