Re: Router Problems
What model Linksys did you get? If it's one of the new E1XXX series, try switching the the wireless channel width to 20Mhz only instead of Auto. You can do this by opening your browser and going to 192.168.1.1. The username and password should be admin for both.
Also, like Chief said, it could be operating at the same channel frequency as other wireless devices in your home. If you have an Android device, download an app called Wifi Analyzer. This will scan all wireless channels within range and show you which ones have the most traffic. You can change your router to operate at the least busiest frequency, and that should improve it if the first suggestion doesn't fix it.
EDIT: Also, who is your ISP?