I have 2 questions

1. How come if I run a web server I have to poke a hole in my firewall(hardware firewall in d-link router) and route it to the correct local ip, but when kazaa or aim are running nothing has to be done to the firewall and nothing has to be done to route requests to the correct machine?

2. I have a few computers and one of them is the family computer. At some point in the past I must have had the family computer save my logon and password for this site. All you have to do is type the first letter of my nickname and your in my account because it fills in the rest for you. How do I get rid of this? I have heard some people say a friend has gotten on their account and assigned a bunch of ap's and I don't want that to happen. I have tried going to internet options and deleting cookies/temp int files/history, but that didn't work. What should I do?

Thanks in advance for any replies.