Issue with mutiple report server instances in azure.

[Deva]

We are trying to use the new app fabric cache as a out of proc session state provider in azure.  This seems to be the only one that microsoft recommends (the table storage one has issues w/ concurancy, and the sql azure one seems to be more of a hack - that some folks have gotten working, we were able to get the site up, but could not get telerik to render our reports with it), so we decided to spend our time on the method that microsoft recomends, app fabric cache... we were able to configure it, and the site that hosts our wcf ReportServer.svc comes up without throwing any exceptions - which indicates our session state is in play.  Yet when we go to render a 3 page report, we get the following error (seen in fiddler looking at the text reply (status 500)) :

<b> Description: </b>An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.

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<b> Exception Details: </b>System.InvalidCastException: Unable to cast object of type 'System.Text.CodePageEncoding' to type 'System.Text.Encoding'.<br><br>

<b>Source Error:</b> <br><br>

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An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.</code>

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<b>Stack Trace:</b> <br><br>

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[InvalidCastException: Unable to cast object of type &#39;System.Text.CodePageEncoding&#39; to type &#39;System.Text.Encoding&#39;.]

ReadInternalEncoderBestFitFallbackFromXml(XmlReaderDelegator , XmlObjectSerializerReadContext , XmlDictionaryString[] , XmlDictionaryString[] ) +648

System.Runtime.Serialization.ClassDataContract.ReadXmlValue(XmlReaderDelegator xmlReader, XmlObjectSerializerReadContext context) +106

System.Runtime.Serialization.XmlObjectSerializerReadContextComplex.InternalDeserializeInSharedTypeMode(XmlReaderDelegator xmlReader, Int32 declaredTypeID, Type declaredType, String name, String ns) +542

System.Runtime.Serialization.XmlObjectSerializerReadContextComplex.InternalDeserialize(XmlReaderDelegator xmlReader, Type declaredType, String name, String ns) +109

Any one have any ideas or can anyone suggest any alternatives... as at present we are not able to scale out our reports