QMediaPlayer doesn't release files after playing them on Windows

After playing files using QMediaPlayer::setMedia() they are not properly released. This results in problems deleting them while the Qt app using QMediaPlayer is still running. After closing the app everything is fine again.

Steps to reproduce on Windows 7 (32/64 bit)
1. Create QMediaPlayer
2. Use QMediaPlayer::setMedia() to open a locale file 'File-A'
3. Use QMediaPlayer::play() to play it
4. Open another file ('File-B') using setMedia()
5. Play that other file
6. Use a program to show open files. E.g. 'process explorer'
7. See that File-A and File-B are open

What I've tried without success:

• Using QMediaPlayer::stop() before using QMediaPlayer::setMedia() again.
• Using QMediaPlayer::setMedia() with null QMediaContent.
• Deleting the QMediaPlayer instance and recreate it

Because even deleting the QMediaPlayer instance does not help I suspect the problem being inside the mediaservice plugin.

I've tried several versions of Qt and QtM compiled with gcc and MSVC++ for 32 and 64 bit Windows 7.
The problem does not occur on Linux.