Comment 1 for bug 355127

I assume you where using ntop 3.3. Actually the ntop password should have been asked during package installation, unless you were running in non-interactive mode and debconf was not able to ask the password.
However, in the the Debian upload 4.0.3+dfgs1-2 this problem will be fixed. I'll ask for a sync to natty.
Thanks for taking the time to report the issue.