I'm running into an issue when using the Infragistics Silverlight tools version 2010.1 with Infragistics Silverlight Data Visualization version 2009.2.  My issue is that when building the solution it throws this exception:

Error 1 The "ValidateXaml" task failed unexpectedly.
System.TypeLoadException: Could not load type 'System.Runtime.Versioning.TargetFrameworkAttribute' from assembly 'mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'.
   at System.ModuleHandle.ResolveType(Int32 typeToken, RuntimeTypeHandle* typeInstArgs, Int32 typeInstCount, RuntimeTypeHandle* methodInstArgs, Int32 methodInstCount)
   at System.ModuleHandle.ResolveTypeHandle(Int32 typeToken, RuntimeTypeHandle[] typeInstantiationContext, RuntimeTypeHandle[] methodInstantiationContext)
   at System.Reflection.Module.ResolveType(Int32 metadataToken, Type[] genericTypeArguments, Type[] genericMethodArguments)
   at System.Reflection.CustomAttribute.FilterCustomAttributeRecord(CustomAttributeRecord caRecord, MetadataImport scope, Assembly& lastAptcaOkAssembly, Module decoratedModule, MetadataToken decoratedToken, RuntimeType attributeFilterType, Boolean mustBeInheritable, Object[] attributes, IList derivedAttributes, RuntimeType& attributeType, RuntimeMethodHandle& ctor, Boolean& ctorHasParameters, Boolean& isVarArg)
   at System.Reflection.CustomAttribute.GetCustomAttributes(Module decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes)
   at System.Reflection.CustomAttribute.GetCustomAttributes(Assembly assembly, RuntimeType caType)
   at System.Reflection.Assembly.GetCustomAttributes(Type attributeType, Boolean inherit)
   at System.Attribute.GetCustomAttributes(Assembly element, Type attributeType, Boolean inherit)
   at MS.Internal.Xaml.MS.Impl.XamlSystemBinding.AddPairsFromAssembly(XamlSchemaContext schemaContext, Assembly asm, String uri, List`1 pairs)
   at MS.Internal.Xaml.MS.Impl.XamlSystemBinding.SearchForXamlNamespace(XamlSchemaContext schemaContext, String uriString, IEnumerable`1 referenceAssemblies)
   at MS.Internal.Xaml.XamlSchemaContext.GetXamlNamespace(String xmlns, Assembly localAssembly)
   at MS.Internal.Xaml.XamlSchemaContext.GetXamlNamespace(String xmlns)
   at MS.MarkupCompiler.ValidationPass.ValidateXaml(String fileName, Assembly[] assemblies, Assembly callingAssembly, TaskLoggingHelper log, Boolean shouldThrow)
   at Microsoft.Silverlight.Build.Tasks.ValidateXaml.XamlValidator.Execute()
   at Microsoft.Silverlight.Build.Tasks.ValidateXaml.XamlValidator.Execute()
   at Microsoft.Silverlight.Build.Tasks.ValidateXaml.Execute()
   at Microsoft.Build.BuildEngine.TaskEngine.ExecuteInstantiatedTask(EngineProxy engineProxy, ItemBucket bucket, TaskExecutionMode howToExecuteTask, ITask task, Boolean& taskResult) SystemActivityMonitor.SilverlightComponents
 

If I down grade the Infragistics Silverlight Tools to version 9.2 it works fine.  Any help??