There appears to be a bug in how Visual Studio does "Add Service Reference" proxy generation for VB.NET projects.

I ran into this issue when trying to add a service reference to Bing Maps and I believe it is not limited to that. I think it stems from it misunderstanding that enum instance variables cannot be tested for equality using .Equals in VB... not sure why.

I think the solution is to simply replace the offending line:

If Me.enumfield.Equals(value) <> true Then

with

If Not Object.Equals(Me.enumfield ,Value) Then

BTW: DO NOT compare boolean results to True or False as they have done!

Use

If boolean_results Then

or

If Not boolean_results Then

[EDIT 2010-07-07]
Specifically, this block of code is wrong:

<System.Runtime.Serialization.DataMemberAttribute()>  _
Public Property CompareOperator() As SearchService.CompareOperator
    Get
        Return Me.CompareOperatorField
    End Get
    Set
        If (Me.CompareOperatorField.Equals(value) <> true) Then
            Me.CompareOperatorField = value
            Me.RaisePropertyChanged("CompareOperator")
        End If
    End Set
End Property

and should be replaced with this:

<System.Runtime.Serialization.DataMemberAttribute()>  _
Public Property CompareOperator() As SearchService.CompareOperator
    Get
        Return Me.CompareOperatorField
    End Get
    Set
        If Not Object.Equals(Me.CompareOperatorField,value) Then
            Me.CompareOperatorField = value
            Me.RaisePropertyChanged("CompareOperator")
        End If
    End Set
End Property

Made this edit so search engines would pick it up... so I can find my own fix next time I run into it. :) [/EDIT]

[EDIT 2011-09-17]
It is still broken in VS2010 and will break your fixed project when upgrading. Gosh, thanks.
[/EDIT]