Moodle networking (MNet)

Greetings

I have the following problem using Moodle Network connection on two Moodle's (1.9.8): where to go from MoodleB (client) to Moodle A (hub) gives the following message: "You do not have permission to log on remotely. "

Clarified that the two sites configured according to the following manual

http://docs.moodle.org/es/Red_Moodle

Also configure the sessioncookiepath and sessioncookies because I have two moodle's (MoodleB and MoodleC) mounted on the same domain. The MoodleA is in another domain.

Another curiosity: Below the error message ("You do not have permission to log on remotely.") leaves a button ("go"), pressing this I enter in the hub (MoodleA) with the same user who is logged in (if not one is logged in appear the login screen).

I appreciate any suggestions