Agree to your point.
In general I notice 127.0.0.1 manually entered in Unix and not in windows. Reason for making this entry in your system was to make a proper resolution of loopback to 127.0.0.1
Before making an entry in you hostname, try to ping 127.0.0.1 if you get reply as localhost then, you can go ahead with making changes in parameter SAPLOCALHOSTFULL only and try to bounce the instance. if still problem exists then share the dev_rd file again.
Regards,
Anil