Streaming Problems: AppleTV 2ndGen vs. other devices

It appears that the Apple TV 2nd Generation (I have two) has difficulty streaming files that other Apple devices on the same network do not. I have narrowed this down to the ATV being the culprit, but not sure what to do next.

For example, streaming a Netflix movie
- AppleTV stops to buffer for :10 every :20 like clockwork.
- Mac Mini hooked up to same TV & wifi, streams same movie with no problems
- iPad 3G (using same wifi network) streams same movie with no problems
- Just for grins, the Xbox 360 Netflix implementation also streams the movie just fine, no buffering

Also having the same issue with streaming video podcasts (from robust providers with good hosting like Revision 3)
- Diggnation (Small Quicktime Video) - never plays after 2 minutes of buffering
- Same file, same wifi Mac Mini - plays instantly
- Same file, same wifi iPad and iPhone 4 - plays instantly

In the case of video podcasts, I never had any stream buffering issues with either one of my Apple TV 1st Gen devices hooked to the same wifi.

These comparisons lead me to conclude that there is some software or hardware glitch on the Apple TV 2nd Generation devices that is hindering its ability to stream content efficiently. I have a hard time believing I got TWO defective units - is anyone else able to run comparison testing like this and get similar results?

Thanks in advance for any advice or suggestions you may have.