Jicbulk,
Have you tried another Router? If you try connecting to another router is the issue still happening?
Also, can you try installing the latest firmware for the router? They released a new one last week:
http://www.asus.com/Networking/RTN65U/HelpDesk_Download/
By the Way, You mentioned before that another computer (Dell Laptop) with N 6205 is working fine. What is the Operating System running on that computer?
Kevin M