Well, problem solved somehow. I just selected restore original settings and immediately could get connected. So, everyone with an N900, you can cruise Carnival now. The cost was about 40 cents a minute, which is steep but not astronomical.

By the way, it appears that internet access is throughout the ship and not just limited to a few areas, which is nice. The ship is the Carnival Splendor, said to be carrying 3000 passengers.