[stomachmonkey]

Also depends on where everything is located.

Wireless does not pass thru angular structures very well. It likes to go straight thru walls and floors. Things like stairs or other non vertical/horizontal structures cause problems. If the router has antennae you can try moving them for better broadcast.

Also glass, especially mirrors are a killer.

Try assigning different channels on the router to see if it clears up any interference from things like 2.4 phones.