Keyboard isn't responsive after unlock OS-X (Mavericks) using AppleScript

Question

I'm using AppleScript to lock the Mac from an external device (trigger) and unlock it from this same device.

Locking works great but when unlock my Mac keyboard and pads becomes unresponsive. Weird thing is when I move mousse after locking and get the password login if I enter the password the unlock makes keyboard responsive and only then.

Is it some kind of security settings I'm not aware of? How could I solve it?

Here is the script I'm using:

Lock:

tell application "System Events"
tell security preferences
set require password to wake to true
end tell
end tell

activate application "ScreenSaverEngine"

Unlock:

tell application "System Events"
tell security preferences
set require password to wake to false
end tell
end tell

tell application "ScreenSaverEngine" to quit

Please help I'm desperate. Also if you have another method you know to lock/unlock my Mac using code I would love to try it out!

Thanks!

UPDATE: To be clear when removing the password setting code (require password) the issue doesn't appear. Meaning removing those 3 lines:

tell security preferences
    set require password to wake to true
end tell

Doesn't have this issue, this is why I think it could be some security thing I'm not aware of.

UPDATE (26 Dec 2013): I didn't find any solution and bounty finished so what I'm doing is inserting my password using ActionScript (maybe this could help others having same issue). If you do have another solution I would love to know.

Answer 1

Try below for locking the screen, I am using the same and no issues while locking or unlocking. Hope this helps.

try
tell application "System Events"
    set the process_flag to (exists process "ScreenSaverEngine")
end tell
if the process_flag is true then
    ignoring application responses
        tell application "System Events" to quit
    end ignoring
else
    set the target_app to ((path to "dlib" from system domain as string) & "Frameworks:ScreenSaver.framework:Versions:A:Resources:ScreenSaverEngine.app") as alias
    tell application (target_app as string) to launch
end if
end try