When my z2 is playing tracks within my Library from an album sometime it will skip some tracks as if they have been deleted from the unit. However, when I manually touch the screen on the track it will play later on. What's Up?

its a heat issue with your HD your on the threshold of it not booting properly.

I had the same issue than it started freezing on startup. You will need to install the Pioneer firmware update. that was just released this past weekend.

i had this happen as well

firmware updated on 9/26 .... hopefully that will fix everything