i have the same problem. nothing is wrong with the router. all my other roommates computers work and stay connected to the internet. my phone stays connected too but my asus laptop keeps disconnecting. i have to restart the computer to get connection for maybe a few minutes until the computer disconnects itself. The computer can see the wireless signal of my router and stays connected but the internet connection is lost.
i have a ASUS RT-N66U Dual-Band Wireless-N900 Gigabit Router.
Laptop: ASUS K53SV Intel® Core™ i7-2630QM 6GB DDR3 NVIDIA GeForce GT 540