I was finally able to solve this stupid problem. I had read in one of the other reddit forums, somebody reflashed the latest BIOS and it worked for them. And since I had ran out of all other options, I thought I would try that.
So, i used this guide http://www.ahowto.net/windows/downgrading-asus-notebook-bios/ to reflash the latest BIOS since my BIOS version was already up to date and the WINFLASH utility does not allow to flash the same BIOS.
After the flashing was done, I tried using the power button and the manual sleep option from the power menu and they both worked.
PHEW!! Good luck to you guys.
Man! I made my account here just to send you a BIG FAT THANKS!!!! you saved me. it was such a stupid thing but annoying as hell. Thank you very much