[A]Microsoft.Reporting.WebForms.ReportHierarchy cannot be cast to [B]Microsoft.Reporting.WebForms.ReportHierarchy.

Ok, I have a strange problem here. I'm using V10 of the reportviewer. The report runs perfectly fine but when I attempt to use anything like Export, I get this error:

Server Error in '/YOURSITE' Application.
--------------------------------------------------------------------------------

[A]Microsoft.Reporting.WebForms.ReportHierarchy cannot be cast to [B]Microsoft.Reporting.WebForms.ReportHierarchy. Type A originates from
'Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' in the context 'Default' at location
'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.WebForms\10.0.0.0__b03f5f7f11d50a3a\Microsoft.ReportViewer.WebForms.dll'.
Type B originates from 'Microsoft.ReportViewer.WebForms, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' in the context
'Default' at location 'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.WebForms\11.0.0.0__89845dcd8080cc91\Microsoft.ReportViewer
.WebForms.dll'.
Description: 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.

Exception Details: System.InvalidCastException: [A]Microsoft.Reporting.WebForms.ReportHierarchy cannot be cast to [B]Microsoft.Reporting
.WebForms.ReportHierarchy. Type A originates from 'Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral,
PublicKeyToken=b03f5f7f11d50a3a' in the context 'Default' at location 'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.WebForms\
10.0.0.0__b03f5f7f11d50a3a\Microsoft.ReportViewer.WebForms.dll'. Type B originates from 'Microsoft.ReportViewer.WebForms, Version=11.0.0.0,
Culture=neutral, PublicKeyToken=89845dcd8080cc91' in the context 'Default' at location 'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.
WebForms\11.0.0.0__89845dcd8080cc91\Microsoft.ReportViewer.WebForms.dll'.

Source Error:

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.

Stack Trace:

[InvalidCastException: [A]Microsoft.Reporting.WebForms.ReportHierarchy cannot be cast to [B]Microsoft.Reporting.WebForms.ReportHierarchy.
Type A originates from 'Microsoft.ReportViewer.WebForms, Version=10.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' in the context
'Default' at location 'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.WebForms\10.0.0.0__b03f5f7f11d50a3a\Microsoft.ReportViewer
.WebForms.dll'. Type B originates from 'Microsoft.ReportViewer.WebForms, Version=11.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91'
in the context 'Default' at location 'C:\Windows\assembly\GAC_MSIL\Microsoft.ReportViewer.WebForms\11.0.0.0__89845dcd8080cc91\Microsoft
.ReportViewer.WebForms.dll'.]
   Microsoft.Reporting.WebForms.ViewerDataOperation..ctor() +289
   Microsoft.Reporting.WebForms.ReportDataOperation..ctor(Boolean requiresFullReportLoad) +118
   Microsoft.Reporting.WebForms.ReportDataOperation..ctor() +34
   Microsoft.Reporting.WebForms.ExportOperation..ctor() +29
   Microsoft.Reporting.WebForms.HttpHandler.GetHandler(String operationType) +206
   Microsoft.Reporting.WebForms.HttpHandler.ProcessRequest(HttpContext context) +180
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +341
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +69

 


--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.17929

Also, when I click Print, I get "Unable to load client print control."