D-Link Randomly Drops Internet

My father recently decided to get Comcast cable internet. The router installation went smoothly and all was well for about an hour. Right before I was going to leave, my step-mother tells me that the internet stopped working. At this point, I am able to log into the router (wired and wirelessly), the router status shows an IP address, but I cannot ping or send any information out. I powercycled, changed the channel of the wireless from 6 to 9, and left, and he called me today to inform me it went down. Again, powercycling fixed the issue.

He is using a D-Link DIR-615 and two laptops, one with Vista and the other with XP. The Vista laptop is brand new. The only resolution for the problem seems to be to powercycle the router and it works without a problem. Before I take the hour-long drive back to his house and attempt to fix the issue, I'd like to be able to head back with more then firmware in my hands. What's strange to me is that I can log into the router and surf the interface, I just can't surf on the internet. Any ideas?