enabling new domain breaks entire web server

i have 34 working virtual domains on my 10.5.7 Server. i've duplicated one of the working domains and edited "Domain Name", "Host Description", "Web Folder" and both log locations for a new (35th) virtual domain. enabling this new domain brings down the web server so that ALL sites are unreachable: "Safari can’t connect to the server..." simply checking or unchecking the box next to this new domain, and clicking 'Save', changes whether the web server is reachable or not. i can't figure out what is causing this. any ideas? thanks!