I learned this one the hard way.  After a lot of searching through DD-WRT forums and time with my cable company doing some communication checking, I accidentally confirmed an obscure item I found in the DD-WRT forums .

If you have any Apple device on your home network (particularly iPad and Macbook), turn off the DNSmasq for DNS option in the DD-WRT Router.

There is something with Apple devices that causes the wireless connection to drop for 5-15 seconds or longer every several minutes when this option is enabled in DD-WRT.  It’s very frustrating when you’re trying to be productive on the net.  It took me a while to confirm that this was the problem, until I mentally associated the start and end of the connection drops with my son coming into or going out of my house with his MacBook Pro.

The best (and most painful) example for Ocham’s Razor that I have ever experienced.