New AAC encoding in QT 7.6

Question

Anybody re-encoding the whole iTunes Library?
There is definitely a difference with 128 AACs.
Made a test with LOGIC and old and new versions did not cancel out with phase inverted.
Although they cancel out better with a one sample delay put on one channel. (forgot on what channel)
Apple lossless and AIF still result in silence.

Answer 1

The technic I used is common with audio work stations for finding out if two files are identical.
You take two files, play them back at exactly the same time but invert the phase of one track.
If you don't hear anything on the output, the sound files are identical. This is not the case with an AAC track converted with QT 7.6 compared with a file generated with QT 7.5.5. You can hear a very thin sounding version of the original file. Difficult to show as a screenshot
Don't worry too much about my test. Its just a theoretical thing.
I guess normal listeners won't hear any difference.