my bad, it was my files that had a problem. So (1) isn't a problem with the dap. But the volume spike phenomena still occurs unfortunately. And there's yet another bug:   Pressing the forward button (physical button) does not skip the song properly through the list of songs. Eg while...

  I did a factory reset but still got the above bugs actually. I'll continue testing to see if its a flac problem (for (1)) and if (2) consistently occurs (happened twice so far). Really hope its a firmware thing and the next firmware release will cure it all!

I've encountered a few bugs with my DX90, does anyone have similar problems?   1) certain flac files play but midway through it skips to the next track. 2) When the DX90 is left playing for several hours (eg during burning in), when I press the screen button to switch the screen back on...