strange behaviour calling method of wcf from powershell using new-webproxyservice - wcf

Question

Can someone explain this to me:
I builded an really simple wcf service for testing purposes.
Consuming service from powershell using New-WebServiceProxy I found this stange behaviour:
if in wcf service I have this kind of Contract returning an int:
[OperationContract]
int GetDictionaryLength();
calling this method in powershell gives an error and the definition of the method is not what I would expect to see
PS C:\ps> $a | Get-Member getdictionarylength | fl *
TypeName :
Microsoft.PowerShell.Commands.NewWebserviceProxy.AutogeneratedTypes.WebServiceProxy1_022s_pwdservice_svc_wsdl.PWDService
Name : GetDictionaryLength
MemberType : Method
Definition : System.Void
GetDictionaryLength(System.Int32&,
mscorlib, Version=4.0.0.0,
Culture=neutral,
PublicKeyToken=b77a5c561934e089
GetDictionaryLengthResult,
System.Boolean&, mscorlib,
Version=4.0.0.0, Culture=neutral,
PublicKeyToken=b77a5c561934e089
GetDictionaryLengthResultSpecified)
changing the contract like this:
[OperationContract]
string GetDictionaryLength();
do a great job called in powershell.
Why this?
WCF is in .net 4.0
Powershell is V2

Answer 1

Experimenting with your answer, and then finally discover this answer, it seems all your problems will go away if you simply add [XmlSerializerFormat] to the operation contract, and the method signature will return to normal. At least my problems did when testing against a 2.0 .Net framework and powershell.

Answer 2

finally I've discovered this:
PS C:\ps> [int]$int = 0
PS C:\ps> $bool = $true
PS C:\ps> $a.DictionaryLength([ref]$int, [ref]$bool)
PS C:\ps> $int
61
I've build a solution with .net 2.0 (powershell native framework) for a client application to consume my wfc (.net 4.0)
and the definition for method DictionaryLegth() was:
void myservice.DictionaryLength(out int DictyionaryLengthResult, out bool DictonaryLengthSpecified)