Api error: Authentication Failed

[Arturo]

I'm trying to use the api, the user logged on successfully, the IP is licensed, but it returns this error:

 

response:
array(2) {
 ["result"]=>
 string(5) "error"
 ["message"]=>
 string(21) "Authentication Failed"
}

request->
array(4) {
 ["username"]=>
 string(7) "apiuser"
 ["password"]=>
 string(32) "md5xxxxxxxxxxxxxxmd5"
 ["action"]=>
 string(21) "getclientsdatabyemail"
 ["email"]=>
 string(23) "someuser@gmail.com"
}

[thehost5968]

has the calling server IP been added to Security >> API IP Access Restriction.