SPN for sql server service

Hi all,

I'm trying to set an spn for sql server service

I'm in my DC machine and execute:

setspn -a MSSQLSvc\SQL_SRV:1433 MyDOMAIN\MyUser

where SQL_SRV is the sql server machine in MyDomain. At first sight, all

it's OK. I get an "updated object" return message. But then If I execute:

setspn -l SQL_SRV

the sql service, doesn't appear. Also, If I see MyUser properties in AD

delegation tab, and try to select the service, it doesn't appear.

Another extrange think it's that, I've created MyUser, totally new, it means

that delegation tab in AD propertiers, doesn't appear (it's correct), then,

I've executed the setspn, and then, delegation tab appears ¿?

Anyone can help me???

Thanks a lot, regards.