First off to get rid of the popup open zone alarm and select the alerts window. Uncheck 'show the alerts pop up window' and the program will not alert you every time it blocks access. To find out who owns the server make sure the relevant alert is showing in the 'Current alerts' window and hit more info. This will take you to a page at Zone Labs website which gives loads of info on what the alert means. In addition hit the 'Who is this' link at the top of this page under the offending ip number and it will take you to a 'whois' search page. If you want to complain to the servers admin then send an email to abuse@(insert domain name from whois search here) stating the ip address causing the alerts, your location and the time. Even better send a copy of the Zone Alarm log with the email.
In your case the IP address is registered to a Danish ISP called Cybercity. So if you haven't visited their site or know who they are then its likely someone on their network is 'pinging' your address for what ever reason. You could try logging off and reconnecting to the net as most ISP's give you a different IP address every time you log on.
Hope this helps
