Just to be clear, is the router killing wifi (as in anyone connected to it gets bounced), or is your laptop killing it's wireless connection (you and others still have internet access, just your system is now running over the wired instead of wireless when connected).

The reason I ask is that often times the latter is the default configuration--when you connect a wired connection to many laptops, it drops wi-fi for the (typically) faster and more responsive cabled connection.