[Sound] Foobar2000 does not terminate correctly when closed while sound is playing

ros gcc dbg bootcd r70203
on VBox 4.3.34 with AC97 driver
Foobar2000: 1.3.9 same symptom as 1.1.18

Normally you can open / close foobar2000 without any issues.

But when you try to close it while sound is still playing, the process will stay in memory & sound will play endless loop (of sound buffer content)

You can kill the foobar2000 process manually and sound mutes.

Sometimes you can not shut down ros then before you killed foobar process.

Search for "Terminated normally." in react-r70203-foobarShutDown.log
It was the last output generated after closing foobar2000.
The process was still running afterwards.
Within this log the system was able to shutdown afterwards without killing the process.