Tested on latest source snapshot, built with VS2010. Window.KeyPressed gets incorrect KeyEventArgs when right alt (AltGr) is pressed. Dump from the debugger (unmodified Window sample):
+ e {[KeyEventArgs] Code(LControl) Alt(True) Control(True) Shift(False) System(False)} SFML.Window.KeyEventArgs
You can see that Control flag is set, ant Code is LControl.
Left alt works as expected:
+ e {[KeyEventArgs] Code(LAlt) Alt(True) Control(False) Shift(False) System(False)} SFML.Window.KeyEventArgs