Like its author, Nmap isn't perfect. But you can help make it better by sending bug reports or even writing patches. If Nmap doesn't behave the way you expect, first upgrade to the latest version available from http://nmap.org. If the problem persists, do some research to determine whether it has already been discovered and addressed. Try searching for the error message on our search page at http://insecure.org/search.html or at Google. Also try browsing the nmap-dev archives at http://seclists.org/. Read this full manual page as well. If nothing comes of this, mail a bug report to <nmap-dev@insecure.org>. Please include everything you have learned about the problem, as well as what version of Nmap you are running and what operating system version it is running on. Problem reports and Nmap usage questions sent to <nmap-dev@insecure.org> are far more likely to be answered than those sent to Fyodor directly. If you subscribe to the nmap-dev list before posting, your message will bypass moderation and get through more quickly. Subscribe at http://cgi.insecure.org/mailman/listinfo/nmap-dev.

Code patches to fix bugs are even better than bug reports. Basic instructions for creating patch files with your changes are available at http://nmap.org/data/HACKING. Patches may be sent to nmap-dev (recommended) or to Fyodor directly.