Its a void-pointer so print out its address and not a number xD
Addresses are hex so use printf(Address: %X", on_esc);

That's fine because we now know your on_esc pointer gets not overwritten/ set to NULL.
The problem apparently is your keyboard or some other hardware/ driver issue. Have you tried to execute your code on some other PC (for example as an executable)?

I have noted it works better when the computer is restarted, but seems to only work for short amount of time.. I guess im kinda re-leaved its not 3dgs :?

Do you have another program like photoshop or something similar?

http://superuser.com/questions/211556/photoshop-causing-other-programs-not-receive-esc-key

omg Emre!!!!!! Thats the glitch!! its that damn photoshop CS2!!!!!!!!!!!

THANK YOU!!

You are welcome