Exchange 2010 mailbox database creation error access denied

Exchange 2010 and the Exchange Trusted Subsystem

In this case, the problem was initially manifesting itself as the following error when trying to create a new mailbox in the first database created with installation of the server: 
Active Directory operation failed on adserver.domain.com. This error is not retriable. Additional information: Insufficient access rights to perform the operation. 
Active directory response: 00002098: SecErr: DSID-03150E8A, problem 4003 (INSUFF_ACCESS_RIGHTS), data 0 
The user has insufficient access rights.

Further it was found that the customer got a similar error when trying to create a new database: 
Active Directory operation failed on adserver.domain.com. This error is not retriable. Additional information: Access is denied. 

--> please see the rest on the blog : http://blogs.technet.com/b/richardroddy/archive/2010/07/12/exchange-2010-and-the-exchange-trusted-subsystem.aspx