I took some more screen captures during tonight's show. The screen captures were taken from mix-1 on my GUI display (DVI-1), but the same tearing occurs on my stage output (DVI-2). You can clearly see where the top 10 or so lines are out of sync with the rest of the image.
Because of the labeling on my input preview window there's no way to see if they are showing up "torn" in that window (since the tear is right at the top of the image) but my Nocturne engineer is top shelf and he'd definitely notice if it was coming from him. The signal corruption is definitely downstream of the switcher (either on the Phoenix card or in Catalyst).
Because of some unrelated issues that I had to deal with today I was unable to check drivers or trouble shoot as suggested, but will do so on the next show day. Meanwhile please take a look at the newer sample images and let me know if this looks familiar.
Thank you.