python - Django and SQL Server - Error when charfield > 10 chars -

i'm using django 1.2.3 , django-pyodbc.

i receiving error when adding user length > 10chars:

the data types nvarchar , ntext incompatible in equal operator

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whenever add user username of 10 characters or below works fine, same error emails.

any idea folks?

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the user table:

create table [auth_user] (     [id] int identity (1, 1) not null primary key,     [username] nvarchar(30) not null unique,     [first_name] nvarchar(30) not null,     [last_name] nvarchar(30) not null,     [email] nvarchar(75) not null,     [password] nvarchar(128) not null,     [is_staff] bit not null,     [is_active] bit not null,     [is_superuser] bit not null,     [last_login] datetime not null,     [date_joined] datetime not null ) 

i had similar problem sql server 2008 , sql native client odbc driver. upgrading sql server 2008 r2 fixed problem. seemed caused issue results sqlgettypeinfo() odbc call wvarchar type including date/time types too.