Set-MailboxRegionalConfiguration - Problem

Hello,

we have Exchange 2010 SP2 Update Rollup 5 v2 with DAG installed. After having created a new user we try to set the mailbox regional configuration. 

1. Brand new user nothing changed:

Get-MailboxRegionalConfiguration newuser -DomainController DC01 | fl

Output:

RunspaceId                            : ae1e80db-0c12-45d5-9cc0-99f415e7357e

DateFormat                            :

Language                              :

DefaultFolderNameMatchingUserLanguage : False

TimeFormat                            :

TimeZone                              :

Identity                              :

IsValid                               : True

2. Setting the regional settings.

Set-MailboxRegionalConfiguration -Identity "New User" -Language pt-br

3. Checking the configuration

Get-MailboxRegionalConfiguration newuser -DomainController DC01 | fl

RunspaceId                            : ae1e80db-0c12-45d5-9cc0-99f415e7357e

DateFormat                            : d/M/yyyy

Language                              :

DefaultFolderNameMatchingUserLanguage : False

TimeFormat                            : H:mm

TimeZone                              :

Identity                              :

IsValid                               : False

WARNING: The object contoso.com/Users/New User has been corrupted, and it's in an inconsistent state. The following validation errors happened: WARNING: Neither DateFormat nor TimeFormat can be set before a language is selected.

When doing the same on Exchange 2010 SP2 UR2 or Exchange 2013 (both in seperate testing environment) we do not get any failure.

Thanks in advanced for your help.