This is a result of the audio engine changes and will likely be resolved by the same fix that is being readied for 5.08, though updating very outdated audio drivers can help as the cause is baasically that the hardware supports only 32 voice channels (compared to sound cards and mixing units having 128 - 256 voices). with certain old drivers bundling older APO modules the windows audio device graph resets and audio doesn't return when too many voices are processed at once.