It does it with any window, even notepad. I even try using the recorder, which is what produced the code below.
#region --- ScriptWriter generated code Start ---
Opt("WinWaitDelay",100)
Opt("WinTitleMatchMode",4)
Opt("WinDetectHiddenText",1)
Opt("MouseCoordMode",0)
WinWait("Untitled - Notepad","")
If Not WinActive("Untitled - Notepad","") Then WinActivate("Untitled - Notepad","")
WinWaitActive("Untitled - Notepad","")
Send("hey")
#endregion --- ScriptWriter generated code End ---