Broken Reference.vb generated after update to VS2012 - vb.net

Question

In my WCF service I have the following OperationContract:
<OperationContract()>
Function getResults(ByVal Settings As Dictionary(Of String, String)) As IO.Stream
...and MessageContract:
<MessageContract()>
Public Class FI
Implements IDisposable
<MessageHeader(MustUnderstand:=True)_
Public id as Integer
<MessageHeader(MustUnderstand:=True)_
Public token as String
<MessageHeader(MustUnderstand:=True)_
Public length as Long
<MessageHeader(MustUnderstand:=True)_
Public del as Char
<MessageHeader(Order:=1)_
Public stream as System.IO.Stream`
Public Sub Dispose() Implements IDisposable.Dispose
FI.Close()
FI=Nothing
End Sub
End Class
On the client side after configuring the service in VS and updating I get multiple errors:
1) For getResults: Instead of the Dictionary an ArrayOfKeyValueOfstringstringKeyValueOfstringstring is expected. I already declared the operation contract as <OperationContract(), ServiceKnownType(GetType(Dictionary(Of String, String)))> without success. My client settings are CollectionType = Generic.List and DictionaryCollectionType = Generic.Dictionary. I also tried deleting and adding the service again.
2) For FI: The method signature that uses the MessageContract FI expects the parameter del to be of type Integer. Here I have no idea what to do.
I have to add, that everything was working fine until recently, the only change I can remember is updating Visual Studio from 2010 to 2012.

Answer 1

I just found out that the underlying problem was an update to .NET 4.5. That's what I did on the machine running VS2010 where the generation used to work. Downgrading to .NET 4.0 did the trick. The generation from within VS is working again.
In conclusion: not a problem of the VS version but of the .NET version of the machine where VS is executed. I guess that the svcutil (or whatever resource the "Update Service Reference" function in VS uses) contained in .NET 4.5 is responsible for the bug.