So unless I'm experiencing the "old code programmed the cards in the standby chassis" problem, I believe this update to be inaccurate at this time. You've listed 15.2(1)SY6 as a fixed version of IOS, I'm running that version and have opened a case where we're still experiencing this problem.
Unfortunately, I don't remember how to determine what version of code did the programming for the line cards - so I'm unable to verify my hypothesis. I have not yet reloaded the line card with the interface that has this issue, if someone cares to followup we might determine where this problem lies.
