Ben, I believe that the conflict actually relates to Gizmo and the AirportVS-SASL rather than the IXEG 737 and AirportVS-SASL. My reason for saying this is that the only aircraft that I have sound issues with both use Gizmo and when flying other aircraft with AVS active that do not require Gizmo there are no sound issues, all sound is normal.
Thanks and Happy New Year