Concatenating 2 or more .wav file in vb.net

I updated a answer found at http://ift.tt/1rD5ilR from C# to VB but I get a strange result. The audio is faster than it should be and the 3 wav files (5 seconds, 1 second and 6 second) amount to a file of just over 6 seconds. All the files have the same waveformat (22050Hz Rate, mono, 32bit float).

In this project I am using NAudio.

My code:

Public Shared Sub Concatenate(outputFile As String, sourceFiles As IEnumerable(Of String))
    Dim buffer As Byte() = New Byte(1023) {}
    Dim waveFileWriter As WaveFileWriter = Nothing
    Try
        For Each sourceFile As String In sourceFiles
            Using reader As New WaveFileReader(sourceFile)
                If waveFileWriter Is Nothing Then
                    ' first time in create new Writer
                    waveFileWriter = New WaveFileWriter(outputFile, reader.WaveFormat)
                Else
                    If Not reader.WaveFormat.Equals(waveFileWriter.WaveFormat) Then
                        Throw New InvalidOperationException("Can't concatenate WAV Files that don't share the same format")
                    End If
                End If
                Dim read As Integer
                While (reader.Read(buffer, 0, buffer.Length) > 0)
                    read = reader.Read(buffer, 0, buffer.Length)
                    waveFileWriter.Write(buffer, 0, read)
                End While
            End Using
        Next
    Finally
        If waveFileWriter IsNot Nothing Then
            waveFileWriter.Dispose()
        End If
    End Try
End Sub

The function will be called like this:

Dim m_oEnum As IEnumerable(Of String) = New List(Of String)() From {"c:\1.wav", "c:\2.wav", "c:\3.wav"}
Concatenate("c:\joined.wav", m_oEnum)

Can anyone help me with this? I have a susoiction that it may have something to do with the sample format being 32 bit float.