ok, thanks for the setting pages..
referent to the error, any field go to red because i filled it, and after click send button the message appear. i search input_user.php and it come from line 56 if(is_multisite && current_user_can( 'manage_network_users' )), so i guess i haven't that role at that moment.
hard to explain but in a moment i loss the superadmin rigths (i just knowed that after that because i couldn't access with my password....
here my steps:
1) in myaccount.com i park two domain and make all *.subdomain,
2) i install a clean wp3.0.1 and make it multisite,
(superadmin user used myaccount.com/wp-admin to access)
3) i install wp multi network plugin and wpdev domain mapping
4) i active wp-multi-network in myaccount.com (id=1)
5) i create site2.myaccount.com (id=2)
6) from multi network i create parkdomain1.com (id=3)
7) i create site4.parkdomain1.com (id=4)
and do some test...
today i was forced to redo with forget option my password and guess what: my superadmin user had become a admin user addressed in parkdomain1.com (the seccond network) not in myaccount.com (the original)
well..... i will tell you if something more arrive