TOO MANY REDIRECTS DOMAIN MAPPING

Hi,

I have installed a Wordpress MU and it works, i have to many sites created, but now i try to use domain mapping and it doesn't work. When I select in "Front end redirect should be:" "directed to mapped", it starts to redirect from original domain to mapped domain all the time > opticafabian.com > opticafabian.opti.es > opticafabian.com ...

Whay can I do? I have activated support access.

Thx!