Need Help: Trouble with Wireless Router Connection on MBP

Hi all. I just bought a MacBook Pro (my first Mac ever) and love, love, love it. However, one glitch is driving me crazy. I do *NOT* have an airport but I connect to my cable modem through my netgear wireless router. When my MacBook Pro goes into sleep mode, I lose the connection to the wireless router. I have to go unplug the router to reboot it for the MBP to see it again. I think it has something to do with how it is assigning the IP address. Has anyone else seen this issue? Know how to solve it? Thanks so much.