You might experienced this error while trying to insert records in Table Storage in a multi threaded environment. What you can do is to make it synchronous access in the TableServiceDataContext's AddObject and SaveChanges portion of your code. 

  lock (_lockable)
            {
                this.AddObject("MonitoringEntries", entry);
                this.SaveChanges();
            }

"An error occurred while processing this request."
    [System.Data.Services.Client.DataServiceRequestException]: "An error occurred while processing this request."
    Data: {System.Collections.ListDictionaryInternal}
    HelpLink: null
    InnerException: "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>\r\n<error xmlns=\"http://schemas.microsoft.com/ado/2007/08/dataservices/metadata\">\r\n  <code>EntityAlreadyExists</code>\r\n  <message xml:lang=\"en-US\">The specified entity already exists.\nRequestId:a01504ea-50e2-4e03-ae9e-1b3deefcc529\nTime:2010-07-21T09:47:19.7159778Z</message>\r\n</error>\r\n"
    Message: "An error occurred while processing this request."
    Source: "System.Data.Services.Client"
    StackTrace: "   at System.Data.Services.Client.DataServiceContext.SaveAsyncResult.HandleBatchResponse()\r\n   at System.Data.Services.Client.DataServiceContext.SaveAsyncResult.EndRequest()\r\n   at System.Data.Services.Client.DataServiceContext.SaveChanges(SaveChangesOptions options)\r\n   at System.Data.Services.Client.DataServiceContext.SaveChanges()\r\n   at

...
    TargetSite: {Void HandleBatchResponse()}

You may experience this error while inserting entity in Azure Table Storage if the value of you datetime field is set to DateTime.MinValue. 

"An error occurred while processing this request."
    [System.Data.Services.Client.DataServiceRequestException]: "An error occurred while processing this request."
    Data: {System.Collections.ListDictionaryInternal}
    HelpLink: null
    InnerException: "<?xml version=\"1.0\" encoding=\"utf-8\" standalone=\"yes\"?>\r\n<error xmlns=\"http://schemas.microsoft.com/ado/2007/08/dataservices/metadata\">\r\n  <code>OutOfRangeInput</code>\r\n  <message xml:lang=\"en-US\">One of the request inputs is out of range.\nRequestId:3383f9e5-892d-48ef-9d2d-ef18de70a891\nTime:2010-07-16T08:00:44.6149987Z</message>\r\n</error>"
    Message: "An error occurred while processing this request."
    Source: "System.Data.Services.Client"
    StackTrace: "   at System.Data.Services.Client.DataServiceContext.SaveResult.HandleBatchResponse()\r\n   at System.Data.Services.Client.DataServiceContext.SaveResult.EndRequest()\r\n   at System.Data.Services.Client.DataServiceContext.SaveChanges(SaveChangesOptions options)\r\n   at System.Data.Services.Client.DataServiceContext.SaveChanges()\r\n 

Get ready for Microsoft certification exam for Azure developers later this year or early next year. It's been 10 months now that we are working with Azure. I guess when the exam get released I am ready to take it.

 

http://blogs.msdn.com/b/gerryo/archive/2010/07/08/developer-cert-update.aspx

 

The 2 Scotts have detailed information about Microsoft WebMatrix beta here and here.

I stumbled upon Scott Hanselman's post "What great .NET developers ought to know". There are things that I am already familiar with and I've experienced working in actual projects but I still don't know their exact definitions - like a by-the-book definitions. Some are really tough ones. 

Ayende post his own answers with Scott's questions here.