I feel it's time to revive this thread. I've had a similar problem since Jarvis where if the Win7 screensaver kicks in, Kodi will just minimize and actually block the Windows screensaver until Kodi has been closed. If I have been doing other stuff like browsing while keeping Kodi minimized, Kodi would also block the Windows screensaver from activating.
I upgraded to Krypton today, and in this version the problems just got bigger. If i played music in Jarvis, the music would still play even if Kodi was minimized by the Windows screensaver, but in Krypton the music now pauses until Kodi is maximized again, which is kind of hopeless.
Maybe a solution is to just disable the Windows screensaver, but for me it's a bad one since I only use Kodi for around 10% of the time my machine is active, I also prefer to have Kodi minimized when I don't use it.
I've tried both the built-in "Black" and the add-on "Qlock" screensavers, they mostly produce the same result. "Black" was quite interesting on one occasion on Krypton, where when the Windows screensaver started, the sound crackled for a moment before Kodi was back seemingly in fullscreen and still playing, but when pressing any key it would minimize and pause playback. Maximizing Kodi again made it windowed. I've been unable to reproduce this for a log.
I've been on the XBMC/Kodi bandwagon since Eden, all pre-Jarvis releases handled this fine on my Windows machines. I hope one of the devs have the time to look into it.
As always, thanks to the devs for all the work put into another Kodi release.
Debug log
here if anyone's interested.