I found the problem. It has nothing to do with WCF or SL. The problem is about IO, stream.
If Stream. Read cannot read enough bytes, it will simply not fill the remaining bytes in your buffer, leaving them on their initial value "changing" your file... Read() returns the number of bytes actually read, so cou could do the following to ensure you got all bytes: but of course your self-answer will fix your problem, nevertheless some hints for followers...
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.