On a network you have to set up each site independently. Although the options look the same, some options only count for the site that you are viewing the options from.
This is exactly the functionality I was seeking that led me here. What I really want is a button under each spam comment that says block this ip for 1 month/1 year. This would allow you to cut down on spam with less chance of blocking ip addresses that might be legitimate users (after the ip gets assigned to a non spammer.)
