"A non-blocking socket operation could not be completed immediately" on blocking method

I’m using C# Socket in synchronized mode (I mean that the socking is blocking and I’m using “Send” and not BeginSend) I sometimes get “A non-blocking socket operation could not be completed immediately” after sending data In addition I'm receiving the data using BeginReceive

Does a开发者_开发问答nyone know why I'm getting this exception and what does it mean?