Forum OpenACS Q&A: Re: OpenACS / IPCop / Error: nssock: failed to listen on 200.200.200.200:8000: Cannot assign requested address

You're sure nothing else listens on 8000?  Try netstat -na | grep 8000.  Also, try setting IP in config.tcl to 0.0.0.0 (any address) -- does it come up on 200.200.200.200?