Could some body help me to find out what I am getting the next error?

Code:
Test method OnlineTestService.Test.Service.OnlineTestServiceTest.saveTest threw exception: 
System.Configuration.ConfigurationErrorsException: Error creating context 'contexto': Could not find the dialect in the configuration ---> Spring.Objects.Factory.ObjectCreationException: Error thrown by a dependency of object 'onlineTestService' defined in 'file [C:\TFS\Development\OnlineTest\OnlineTestService.Test\Service.xml] line 9' : Initialization of object failed : Could not find the dialect in the configuration
 while resolving 'testDao' to 'testDao' defined in 'file [C:\TFS\Development\OnlineTest\OnlineTestService.Test\Dao.xml] line 50'
 while resolving 'HibernateTemplate' to 'HibernateTemplate' defined in 'file [C:\TFS\Development\OnlineTest\OnlineTestService.Test\Dao.xml] line 43'
 while resolving 'SessionFactory' to 'SessionFactory' defined in 'file [C:\TFS\Development\OnlineTest\OnlineTestService.Test\Dao.xml] line 15' ---> System.InvalidOperationException: Could not find the dialect in the configuration
Code:
<?xml version="1.0" encoding="utf-8" ?>
<objects xmlns="http://www.springframework.net"
         xmlns:db="http://www.springframework.net/database">


  <object type="Spring.Objects.Factory.Config.PropertyPlaceholderConfigurer, Spring.Core">
    <property name="ConfigSections" value="databaseSettings"/>
  </object>


  <db:provider id="DbProvider"
               provider="SqlServer-2.0"
               connectionString="Data Source=development;Initial Catalog=OnlineTest;User Id=xxxxt;Password=xxxx1;"/>

  <object id="SessionFactory" type="Spring.Data.NHibernate.LocalSessionFactoryObject, Spring.Data.NHibernate21">
    <property name="DbProvider" ref="DbProvider"/>
    <property name="MappingAssemblies">
      <list>
        <value>OnlineTestService</value>
      </list>
    </property>
    <property name="HibernateProperties">
      <dictionary>
        <entry key="hibernate.connection.provider" value="NHibernate.Connection.DriverConnectionProvider"/>
        <entry key="hibernate.dialect" value="NHibernate.Dialect.MsSql2008Dialect"/>
        <entry key="hibernate.connection.driver_class" value="NHibernate.Driver.SqlClientDriver"/>
        <!--entry key="hibernate.hbm2ddl.auto" value="create-drop" /-->
      </dictionary>
    </property>
    <!-- provides integation with Springs declarative transaction management features -->
    <property name="ExposeTransactionAwareSessionFactory" value="true" />

  </object>

  <object id="HibernateTransactionManager" type="Spring.Data.NHibernate.HibernateTransactionManager, Spring.Data.NHibernate21">
    <property name="DbProvider" ref="DbProvider"/>
    <property name="SessionFactory" ref="SessionFactory"/>
  </object>

  <!-- Exception translation object post processor 
  <object type="Spring.Dao.Attributes.PersistenceExceptionTranslationPostProcessor, Spring.Data"/>
  -->
  <object id="HibernateTemplate" type="Spring.Data.NHibernate.Generic.HibernateTemplate">
    <property name="SessionFactory" ref="SessionFactory" />
    <property name="TemplateFlushMode" value="Auto" />
    <property name="CacheQueries" value="true"/>
  </object>


  <object id="testDao" type="OnlineTest.Dao.TestDao">
    <property name="HibernateTemplate" ref="HibernateTemplate"/>
  </object>

</objects>