GameSave Manager, after a scheduled backup task, prevents Windows from going to sleep. There is a gs_mngr_3.exe process still running after the job at a constant 3% of my CPU non-stop and the process uses audio that prevents Windows from going to sleep.
If I kill the process, the sound process disappears from the volume mixer and the "audio stream in use" list.
What does the task log show?
GameSave Manager shouldn't be utilising any 'media' outside of when displaying error prompts, which I assume it is trying--and failing--to render and thus your issue.