I've found that same type of problem in -all- wireless devices I've used, especially when some distance from the source.
I suspect its due to low transmit power(i.e. I can receive, but don't have enough power for the router to see me), as well as the N-type problem.

That all being said, its a hardware, -not- a software problem, I believe - Unless we can somehow boost/overpower the Wifi module(apparently possible with -some- modules - especially router ones - but only with custom firmware).