Since you've already tried changing channels, the problem is most likely with your router. Have a friend/family member bring over their router and test it with your modem and computer.
If you need to buy a new router... get the Linksys WRT54GL and flash the firmware with DDWRT's latest release.
http://www.newegg.com/Product/Produc...82E16833124190
http://www.dd-wrt.com
Also you may want to try updating the firmware on your Netgear router, this may alleviate the issue.
Good luck, let us know how it works out.