is it dangerous to run gtk-gnutella in ultrapeer mode with the selected port open to the world or should I be completely behind a firewall?
At the moment all ports are closed except 7777 (for games) and 8124 (for gtk-gnutella).

edit: It just switched back to leaf mode, I don't know why it did this, this was the first time I had seen it run in ultrapeer mode after months of use.