I understand that in her latter years, QE2 had some problems with her ballast tanks, and that this is fairly common in old ships. I dont think it was a huge problem, but they weren't working like they had done orginally.
I also understand that at her service speed (28.5 knots) she was easier to keep upright than when dawdling/stationary!
When I returned to QE2 for the first time in nearly 21 years for the 2 night party cruise before Christmas 2007, she had quite a list the whole time she was in port - at Southampton and Zeebrugge. Because it being winter, and the itinerary, on that cruise I didn't experience her upright in daylight!! She was upright at sea, but we only did that in the dark on that trip. We had a fairly epic flood in our bathroom from the shower in (unoriginal) cabin 2154 because of the list!