Cubase 6.02 Media Bay Preview Audio Crackling

Note: Problem only occurs using Cubase 6. Cubase 5 is OK!!
I am using Cubase 6.02 64bit
Crackling Audio in MediaBay during Preview under these conditions:

  1. When the ‘Align Beats to Program’ is enabled.
  2. When the duration of the audio file is longer than the Transport Cycle Loop Duration.
    During the crackling, The VST Performance Disk Meter goes in the Red.
    This occurs even in an Empty Project Template.
    If the Tempo of the original Wav file is edited in Media Bay, and then returned to its original value, the problem is gone.

Please not that Media Bay is not busy ‘Scanning’ during this incident!

Under the same conditions using Cubase 5 (using the same empty project template), there is no problem!!! This only happens with Cubase 6!
I have a clean rock solid system dedicated solely to my DAW (Cubase 5 has never given me any problems. Even with heaps of VST Instruments and Audio Plugins being used at the same time, the VST Performance meters are always less than 25 percent of maximum - I have never needed to perform a ‘freeze’ to save CPU Power).

So until this problem can be rectified, I will continue to use Cubase 5.

Has anyone experienced the same issue?