5
Fantastico installations can be problematic for some, since some of the file permissions are owned by the server, not the site owner.
I found this out very early when I signed up my new hosting account. I quickly scrapped my Fantastico install and did it manually to bypass file permissions. In fact, I don't use Fantastico for anything, period. I am much comforted by knowing that I have installed things myself and kept the files up to date. If a host gets behind on their cPanel upgrades, XOOPS suffers because it installs older versions and updates are hard to apply because of file perms.
Anyhow, it still may not solve your problem if it's firewall related, but worth looking into doing an install on your own in the root directory (another thing Fantastico won't let you do). Once completed, just copy your XOOPS db from the Fantastico install into your own (don't forget to add drop tables). Reinstall your mods first, then do the DB upgrade and your good to go.
With any luck you should be up and running, if not, do a firewall search here on the site for a solution, as this would be the only other problem.