DataServiceRequestException with TableStorageSessionStateProvider

I'm trying to use the TableStorageSessionStateProvider from the Azure training kit. I can use the example wit开发者_高级运维hout problems but when I use it in my web app, I get this exception:

System.Data.Services.Client.DataServiceRequestException occurred
  Message=An error occurred while processing this request.
  Source=Microsoft.WindowsAzure.StorageClient
  StackTrace:
       at Microsoft.WindowsAzure.StorageClient.Tasks.Task`1.get_Result()
       at Microsoft.WindowsAzure.StorageClient.Tasks.Task`1.ExecuteAndWait()
       at Microsoft.Samples.ServiceHosting.AspProviders.TableStorageSessionStateProvider.<>c__DisplayClass5.<ResetItemTimeout>b__4()
  InnerException: System.Data.Services.Client.DataServiceClientException
       Message=<?xml version="1.0" encoding="utf-8" standalone="yes"?>
<error xmlns="http://schemas.microsoft.com/ado/2007/08/dataservices/metadata">
  <code>UpdateConditionNotSatisfied</code>
  <message xml:lang="en-US">The update condition specified in the request was not satisfied.
RequestId:c552d552-ba1c-4920-84fc-e716705b58b9
Time:2011-02-17T12:43:38.5650557Z</message>
</error>
       Source=System.Data.Services.Client
       StatusCode=412
       StackTrace:
            at System.Data.Services.Client.DataServiceContext.SaveResult.<HandleBatchResponse>d__1e.MoveNext()
       InnerException: 

I've tried this, but no luck so far.I've also seen null reference exceptions happening, so I guess that the TableStorageSessionStateProvider it's not behaving like the InProc one, so maybe I have to check how sessions are being used in the application. But, what could be the problem ?

EDIT: Well, I've find out that the example in the Azure training kit also fails if you only use the TableStorageSessionStateProvider with the same exception. You just have to comment the other providers:

<authentication mode="Forms">
  <forms loginUrl="~/Account/Login.aspx" timeout="2880" />
</authentication>

<!-- Membership Provider Configuration -->
<!--<membership defaultProvider="TableStorageMembershipProvider" userIsOnlineTimeWindow="20">
  <providers>
    <clear />
    <add name="TableStorageMembershipProvider" type="Microsoft.Samples.ServiceHosting.AspProviders.TableStorageMembershipProvider" description="Membership provider using table storage" applicationName="AzureStore" enablePasswordRetrieval="false" enablePasswordReset="true" requiresQuestionAndAnswer="false" minRequiredPasswordLength="1" minRequiredNonalphanumericCharacters="0" requiresUniqueEmail="true" passwordFormat="Hashed" />
  </providers>
</membership>

<profile>
  <providers>
    <clear />
    <add name="AspNetSqlProfileProvider" type="System.Web.Profile.SqlProfileProvider" connectionStringName="ApplicationServices" applicationName="/" />
  </providers>
</profile>

--><!-- RoleManager Provider Configuration --><!--
<roleManager enabled="true" defaultProvider="TableStorageRoleProvider" cacheRolesInCookie="true" cookieName=".ASPXROLES" cookieTimeout="30" cookiePath="/" cookieRequireSSL="false" cookieSlidingExpiration="true" cookieProtection="All">
  <providers>
    <clear />
    <add name="TableStorageRoleProvider" type="Microsoft.Samples.ServiceHosting.AspProviders.TableStorageRoleProvider" description="Role provider using table storage" applicationName="AzureStore" />
  </providers>
</roleManager>-->

<!-- SessionState Provider Configuration -->
<sessionState mode="Custom" customProvider="TableStorageSessionStateProvider">
  <providers>
    <clear />
    <add name="TableStorageSessionStateProvider" type="Microsoft.Samples.ServiceHosting.AspProviders.TableStorageSessionStateProvider" applicationName="AzureStore" />
  </providers>
</sessionState>
    <machineKey decryption="AES" decryptionKey="F7FA540B4DFD82E5BB196B95D15FF81F5B973B5514F973D2A46B4C52224A3ABC" validation="SHA1" validationKey="5B973B5514F973D2A46B4C52224A3ABC90378EFA9DE62168764FF0DCE537184F0535D5D9AD66DEDC5B973B5514F973D2A46B4C52224A3ABC90378EFA97DC1ABF" />

If you want to know why you're getting this error with the TableStorageSessionProvider see my answer to this question. If you want to know about the using the SQL session provider in Azure see the answer to this question.

If you need to use something today, you're only real choice is to use the SQL session provider even though it's not supported. Once AppFabric Caching is out of CTP it will be the way to go.