low AEBS range?

Bought a AEBS last month. I upgraded from a Linksys G router. My house is around 4-5 thousand sq. ft. Before with my linksys router it reached the master bedroom fine. (Router is located in the opposite corner of the house on the 1st floor). Now i barely get 1 bar or sometimes nothing. Anything i can do besides buying an airport express? I thought these N routers had more range; etc.