Michael.......I access the files on the MS750 hard drive with the Sonos when I choose to listen to the Sonos, not from any files my computer hard drives. Once you create a network bridge on your computer for the MS750 interface, the Sonos can use this network connection to the MS750 hard drive for access to the FLAC files stored there.
I installed my Sonos ZP90 behind my stereo rack cabinet, plugged the ethernet cable that had been connected to my MS750 into the ZP90, then connected another short ethernet cable from the second ethernet connector on the ZP90 back to the MS750. That puts both my MS750 and the Sonos ZP90 on the same ethernet cable back to my router. It works perfectly, no drop outs from trying to make the network connection via wireless. I hope this clears it up for you.
I installed my Sonos ZP90 behind my stereo rack cabinet, plugged the ethernet cable that had been connected to my MS750 into the ZP90, then connected another short ethernet cable from the second ethernet connector on the ZP90 back to the MS750. That puts both my MS750 and the Sonos ZP90 on the same ethernet cable back to my router. It works perfectly, no drop outs from trying to make the network connection via wireless. I hope this clears it up for you.