Theres probably a driver incompatibility issue between the Wifi on the router and the ASUS phone. The WiFi drivers may or may not be fully compliant or out of date thus problems may exist when using N mode. Most Rev A routers unless if there is a critical need or there is a mass problem that prevents proper operation, there probably wont be a fix for this coming from D-Link.
Only other solution possible that might work would be to disable the WiFi on the Rev A and install a D-Link model DAP access point as a WiFi radio upgrade that maybe would work with the Asus device....I'd contact D-Link support and maybe ask them specifically what supports your Asus device...