Stereo image wrong (even at 192kbps "VBR"), second synth sound which is played to the main "melody" synth (higher frequency one, percussion like used, positioned to the right) sounds strange at 128kbps (in addition to being wrongly positioned), didn't bother to check at 192kpbs.

Edit:
Uploaded encoded file(s).

I also can confirm strange behavior of iTunes (6.0.3.5) aac encoder. Here is a killer sample (glockenspiel) even for 320cbr. There are two distinct ringing artifacts in the right channel. The second file contains the version with amplified artifacts for convenience.

Click to view attachment
Click to view attachment

EDIT: Each file contains two samples - reference and encoded/decoded.