Closed Issue: engine.Close does not close [5]

Version 1.4.0.0, Window 7, Visual Studio 2010
There is something wrong with the closing of R (engine.Close): in the following code, after engine.Close the command should fail, but it returns the same value as if the engine had not been closed.

double a = engine.EagerEvaluate("a=c(10,20)").AsNumeric().First();
Console.WriteLine(a);
engine.Close(); // There is something wrong with Close()
// This should fail, but it works the same with the above line present or not
double b = engine.EagerEvaluate("b=c(33,34)").AsNumeric().First();
Console.WriteLine(b);