This post is more a help for the people out there googling to solve this type of problems than a support request.
If your trying to add a IDN (IE. ññ.com) to one of your sites using the domain mapping plugin you're probably gonna find out that this just dont work and your domain keeps redirecting you to the main site in your network.
The easy solution to this is instead of inserting your domain in the non ascii format (ññ.com) just put it in the punicode format that usually starts with the characters "xn--"
It would be a great idea for the next version of this amazing plugin (thanks Donncha) to autoconvert all IDNs to ToASCII to avoid this type of problems.
I know that in english you dont use any non ASCII characters but this wordpress thing is getting more and more popular around the world :D
For more information on IDN & Punicode format, you can check this wikipedia article http://en.wikipedia.org/wiki/Internationalized_domain_name