Airport Extreme with External Hard Drive Connection Issues

As of last month, I have the latest Airport Extreme set up as my home network. I have an external hard drive connected to it through a USB hub (that also connects to a printer). I use the external hard drive to store my iTunes library and iPhoto Library (to access from my MB Air).

Every several days, I keep having the same issue. My Airport will freeze up, kick all of my computers off the network and display a solid yellow light. I am not able to reset it and must leave it alone until it decides to work (and left without internet). I have exhanged it once at the Apple Store and they reported no issues with the Airport Extreme. They did suggest that the cause may be my ISP (Comcast), however. Even with a hard reset of my modem, though, I'm still having the issue.

Any other suggestions as to the cause? It's obviously a big hassle. The hard drive is in good working condition, as far as I can tell. I'm starting to think the Airport Extreme isn't playing well with the WD hard drive.