While setting up Experience manager web service the following exception occurred. Point me where I have configured wrongly. The same exception occurred while browsing for oData.svc as well.

Exception Details:

Exception type: TridionReflectionException 
    Exception message: <JavaException>
  <Type>com/tridion/util/TridionReflectionException</Type>
  <Message><![CDATA[Unable to load request class, was not found on classpath]]></Message>
  <StackTrace><![CDATA[com.tridion.util.TridionReflectionException: Unable to load request class, was not found on classpath
    at com.tridion.util.ReflectionUtil.loadClassInstanceWithTypes(ReflectionUtil.java:67)
    at com.tridion.util.ReflectionUtil.loadClassInstance(ReflectionUtil.java:108)
    at com.tridion.ambientdata.claimstore.providers.ClaimStoreProviderFactory.newClaimStoreProvider(ClaimStoreProviderFactory.java:25)
Caused by: java.lang.ClassNotFoundException: com.tridion.siteedit.preview.PreviewClaimStoreProvider
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.net.URLClassLoader$1.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at java.net.URLClassLoader.findClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source)
    at java.lang.ClassLoader.loadClass(Unknown Source)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Unknown Source)
    at com.tridion.util.ReflectionUtil.loadClassInstanceWithTypes(ReflectionUtil.java:61)
    ... 2 more
   at Codemesh.JuggerNET.JavaClass.ThrowException(Exception ex)
   at Codemesh.JuggerNET.NTypeValue.Throw(Int64 inst)
   at Codemesh.JuggerNET.JavaClass.ThrowTypedException(Int64 inst)
   at Codemesh.JuggerNET.JavaMethod.CallObject(JavaProxy jpo, JavaMethodArguments args)
   at Codemesh.JuggerNET.JavaMethod.CallObject(JavaProxy jpo, Type declaredType, Boolean bLeaf, JavaMethodArguments jargs)
   at Com.Tridion.Ambientdata.Claimstore.Providers.ClaimStoreProviderFactory.NewClaimStoreProvider(AmbientDataConfig config, String defaultProviderClass)
   at Tridion.ContentDelivery.AmbientData.Runtime.AmbientRuntime.Setup()
   at Tridion.ContentDelivery.AmbientData.HttpModule.Init(HttpApplication application)
   at System.Web.HttpApplication.RegisterEventSubscriptionsWithIIS(IntPtr appContext, HttpContext context, MethodInfo[] handlers)
   at System.Web.HttpApplication.InitSpecial(HttpApplicationState state, MethodInfo[] handlers, IntPtr appContext, HttpContext context)
   at System.Web.HttpApplicationFactory.GetSpecialApplicationInstance(IntPtr appContext, HttpContext context)
   at System.Web.Hosting.PipelineRuntime.InitializeApplication(IntPtr appContext)]]></StackTrace>
</JavaException>
com.tridion.util.TridionReflectionException: Unable to load request class, was not found on classpath

Configuration details:

cd_ambient_conf.xml:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration Version="7.1"
               xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
               xsi:noNamespaceSchemaLocation="schemas/cd_ambient_conf.xsd"> 
  <Cartridges>    
    <Cartridge File="cd_webservice_preview_cartridge.xml"/>
  </Cartridges>
  <ClaimStoreProvider>com.tridion.siteedit.preview.PreviewClaimStoreProvider</ClaimStoreProvider>  
</Configuration>

cd_webservice_preview_cartridge.xml:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:noNamespaceSchemaLocation="schemas/cd_webservice_conf.xsd"> 
  <OData>
    <DefaultTop>25</DefaultTop>
    <FixedPublicationId>My publication Id</FixedPublicationId>
  </OData>
  <Accounts>
    <Account Id="tridion" Password="encrypted:fhS6whphjS2G2rG6aI6T/g==">
      <Metadata>
        <Param Name="FirstName" Value="SDL"/>
        <Param Name="LastName" Value="Tridion"/>
        <Param Name="Role" Value="Tridion test account"/>
        <Param Name="AllowedServices" Value="contentService"/>
      </Metadata>
    </Account>
    <Account Id="testuser" Password="testpass"/>
  </Accounts>
</Configuration>

cd_core.log:

DEBUG HttpModule - Ambient Data context initialization.
DEBUG HttpModule - Ambient Data context initialization.
DEBUG AmbientDataConfig - Found claimStoreProvider definition in configuration file: com.tridion.siteedit.preview.PreviewClaimStoreProvider.
DEBUG AmbientDataConfig - Configured ADF cookie prefix: TAFContext.
ERROR XMLConfigurationReader - Error while validating file 'cd_webservice_preview_cartridge.xml' with schema 'schemas/cd_ambient_cartridge_conf.xsd'. cvc-elt.1: Cannot find the declaration of element 'Configuration'.
DEBUG AmbientDataContext - Setting current ambient data context: com.tridion.ambientdata.web.WebContext
DEBUG HttpModule - Init
DEBUG HttpModule - Init
DEBUG AmbientRuntime - Ambient Runtime initialization.
DEBUG AmbientRuntime - Ambient Runtime initialization.
INFO  HTTPHeaderProcessor - The DigestKey was not configured, so no digest will be added to the headers and cookies and they won't be validated!