Swoosh sound from song to song

Hi~

First off - you guys are amazing - truly exceptional software.

Alas… has anyone encountered this:

When playing back hires PCM, 24bit 96, 176 or 192khz, a loud swoosh is heard between tracks… This only happens on hires PCM files, not when playing back DSD or 16/44 PCM.

Any ideas?

MacBook 11" Yosemite - Roon - Playback Designs MPS-5

Thanks!

DK