I get a ton of these:

Active System Attack Alerts
=-=-=-=-=-=-=-=-=-=-=-=-=-=
Jan 8 16:04:25 www portsentry[989]: attackalert: UDP scan from host:
user-12hci5s.cable.mindspring.com/69.22.72.188 to UDP port: 80
Jan 8 16:04:25 www portsentry[989]: attackalert: Host:
user-12hci5s.cable.mindspring.com/69.22.72.188 is already blocked Ignoring
Jan 8 16:13:27 www portsentry[989]: attackalert: UDP scan from host:
user-12hci5s.cable.mindspring.com/69.22.72.188 to UDP port: 80
Jan 8 16:13:27 www portsentry[989]: attackalert: Host:
user-12hci5s.cable.mindspring.com/69.22.72.188 is already blocked Ignoring

Can someone tell me whats going on please?

Not much to say. You have installed portsentry which monitors port opening. When someone tries to scan your machine it blocks the user. There are anyway a lot of false positives.

I was just wondering because there are always from the same host.