[2005] Serializing into a memorystream

[Atheist]

I've got a 2 dimensional string array that I'm trying to serialize into a memorystream, and then read the memorystream using a binaryreader to get a bytearray.
The problem is that my byte array always ends up with nothing but 0's in it.
If I however, serialize to a filestream, it works alright.

Is there something obvious I've missed in my code?
(TileInfo is the 2-dimensional string array)

Dim formatter As Runtime.Serialization.IFormatter = New Runtime.Serialization.Formatters.Binary.BinaryFormatter
        Dim memStream As New IO.MemoryStream
        formatter.Serialize(memStream, TileInfo)
        Using bReader As New IO.BinaryReader(memStream)
            Dim byteArray(CInt(bReader.BaseStream.Length)) As Byte
            bReader.Read(byteArray, 0, CInt(bReader.BaseStream.Length))
            BytesToSend.AddRange(byteArray)
        End Using
        memStream.Close()

Thanks.