I’ve had the same issues with aac files encoded from lossless through iTunes. Two methods worked for me. I used foobar2000 in both cases.
1- Create your aac files using Nero aac command line encoder.
or,
2- Import your iTunes files into foobar2000 and use the mp4 optimization utility on those imports. I optimized 1800 files in under 10 minutes. I loaded the optimized files onto my 32gb card and fired up the clip zip. Worked great. All of the files, tags, and album art loaded to the player correctly. Worked as good as mp3 file loads for me.
Hope this helps.
Jeff S.
