Brand New Mac Mini Stutters While Playing Video

Just picked up a new Mac Mini yesterday (mid range, 2.5 i5 with AMD Radeon video). I hooked it up to my plasma TV and was playing back movies and TV shows via iTunes that I had purchased from iTunes. Every 6 or 8 seconds the video freezes very briefly then continues playing. This occurs regularly. So I hooked up my 4 year old MacBook with an Intel Core 2 Duo and integrated Intel graphics and it played smoothly and flawlessly through every video I through at it.

Any ideas? At the moment I'm pretty ticked I dropped almost a grand yesterday for something that plays video poorer than my 4 year old MacBook with significantly less horsepower.