Clientid Null in json/xml response

Hello, I'm having a big trouble with api response.
I have done, with app engine, a client to use timesheet: tested the app with a free account it works, but when i try to use it with business account, no.
When I ask to myintervals the json corrisponding to my person, this is the response:

{
"personid":"XXXXX",
"status":"OK",
"code":200,
"person":
{
"id":"XXXX",
"title":"",
"firstname":"XXXXX",
"lastname":"XXXXX",
"primaryaccount":"f",
"allprojects":"f",
"username":"XXXX.XXXXX",
"active":"t",
"groupid":"4",
"notes":"",
"lastlogin":
"2010-09-24 15:21:37",
"numlogins":"90",
"clientid":null, <-- no ids here!
"private":"f",
"permids":[]
}
}

Clientid is null!! How is possible? I got a lot of client associated to my person...Is this a bug?

this is the response in my test enviroment with free account
{
"personid":"XXXXX",
"status":"OK",
"code":200,
"person":
{
"id":"XXXX",
"title":"",
"firstname":"XXXXX",
"lastname":"XXXXX",
"primaryaccount":"f",
"allprojects":"f",
"username":"XXXX.XXXXX",
"active":"t",
"groupid":"4",
"notes":"",
"lastlogin":
"2010-09-24 17:31:38",
"numlogins":"90",
"clientid":51116, <---now we got id!
"private":"f",
"permids":[]
}
}

Token, header, and url to make request is right, because in test enviroment it works, so I need an help :(

I hope you understand me, my english is very bad!

Ok, i have just submitted this issue in that form. I need to do something else?

I hope you will help me because this project is for my thesis :)

Thanks