Can't connect to a web site

I'm using Windows XP SP2. I use First Defense ISR which means I have several snapshots or Operating Systems on my computer (4). I can connect to a certain website on two of them but not on the other two. This is true using both Internet Explorer and Netscape so the issue doesn't seem to be browser related. I've flushed the DSL cache, deleted Internet temp files and all temp files. My Internet connection to Comcast, my ISP, is identical in all cases. I have a router with a firewall but I don't believe this could be the case because of the success in half of the snapshots. I've tried connecting after disabling my software firewall to no avail. I would welcome any suggestions.
Thanks a lot!
Dick

 

Never mind. I was able to do an ip search and find a second ip address for the site which allowed me to get up.