Anyone else notice this problem?

The exact same DV source image was loaded into Vegas and rendered out twice as Huff (actually I tried a whole bunch of lossless CoDecs and they all came out the same). The only difference between them is one used Sony's DV CoDec (by selecting "Ignore 3rd party codecs" in Options) and the other wasn't (by unselecting this option.)
The Sony CoDec produced the more "mangled" looking image (it is zoomed 200%). Some dithering artifacts were introduced when I converted the images to GIFs, but it almost looks like the chroma of the Sony render is at half rez.
Sony's CoDec works fine so long as the render format is DV, but using it and rendering to ANY OTHER CoDec is giving me these horrible chroma artifacts.
I have even tried different versions of Vegas and have gotten the same results. Considering that Sony's CoDec is the default setting, I find it hard to believe that I'm the first to notice this. Is it just me?