That usually indicates a connection problem between Logbook software and our website. Sometimes it's just a temporary internet problem, so try again in a few hours and see if it works.
If it still fails, it's usually a firewall issue. Try disabling your firewall just long enough to register, and then re-enable the firewall. If you need help contact our support department during business hours, preferrably when you have high-speed internet access and we can remote-in to your computer and help see what's going on.
--LarryBoy