SendKeys to Lightroom 5 is not working properly

Question

I'm actually developing a little tool to do the shooting review in lightroom of a photographic shooting sessions with a 360 controller.

I'm using the SendKeys method to simulate the key input and the WindowsInputSimulator (http://inputsimulator.codeplex.com/)

I got an issue with the SHIFT+ARROW shortcut to add or remove photo from the current selection. The arrow key is working properly but it look's like the SHIFT modifier isn't. I've tried the following code :

SendKeys.SendWait("+{RIGHT}");

InputSimulator.SimulateModifiedKeyStroke(VirtualKeyCode.SHIFT, VirtualKeyCode.RIGHT)

InputSimulator.SimulateKeyDown(VirtualKeyCode.SHIFT);
InputSimulator.SimulateKeyPress(VirtualKeyCode.RIGHT);
InputSimulator.SimulateKeyUp(VirtualKeyCode.SHIFT);

I've already lost few hours on that :'( Do you have any ideas ?