Linksys Wireless Router :: EA3500 Dropping Internet Connection Every 2 Minute?

 I've recently purchased the EA3500 dual band wireless-N router to replace my old and somewhat tired WRT54GS.  The old router worked, I just decided to upgrade to wireless-N since all of my devices are now capable.My ISP is Comcast and I use a Motorola SB 6120 cable modem. After an extremely easy setup of the new router last week, I experienced one full day of glorious speedier network and internet traffic.  However, roughly 24 hours after installation I started experiencing intermittetent internet connectivity issues.  As in - the cable modem is accessible for 2 minutes and then can't be found for 2 minutes, repeat forever.  
 
After multiple different troubleshooting steps, including rebooting both the modem and the router together, separately, and releasing and renewing the router's IP Address through the router's admin page, I finally ended up resetting the router back to factory defaults and letting Windows 7 guide me through the re-installation rather than using the provided "easy setup" CD from Cisco.
 
This seemed to have worked, but 2 days later, my "every 2 minutes" issue returned.  
 
Something important to note here is that all of my devices - both wired and wireless - are able to communicate with each other without issue.  For example - while I have no access to the cable modem, I am able to stream music from a wired desktop through a wireless laptop to a wireless receiver connected to my TV.  I am also able to access the router's admin tools during my connectivity issues.