Audio/Video sync drift in Premiere CS5.5, but not in CS6

I have a QuickTime file with the following specs:

Video: H.264, 854x480, 29.99fps

Audio: AAC, 44100 Hz

When I open the file in QT player, or in Adobe Premiere CS6, there is no issue with Audio/Video sync.

However, when I import the file in Premiere CS 5.5, there is a drift in the Audio/Video sync.

Is there something I can do in Premiere CS 5.5 to avoid or fix the drift?

Thanks.