Problem: 10-bit QuickTime (QT) Cineform footage in Premiere CS6 on Windows 7 looked ok with Sequence in 8-bit mode but crazy (mostly noise) when same Sequence was in “Maximum bit depth” mode.
Solution: Re-wrap the footage as AVI-Cineform (or else use Premiere CS5.5 or a different NLE).
I posted this on the Adobe Premiere forum at http://forums.adobe.com/thread/1268633