Another good thing to remember is that if you are using bookmark links to get into the site remember to only bookmark a login protected site BEFORE logging in and not after. Once you log into a site, a unique session ID number is created. If you bookmark a site while in a unique session, this can sometimes cause problems with the bookmark link down the road. So remember for sites that require logging in, if you would like to bookmark them please do so in a Logged Off state.
NOTE: If you happen to have a firewall program installed and running on your computer, this will also block you from logging in. You may need to disable the firewall while logging in and then re-enabling it after you've logged on.