something like this maybe?
http://community.skype.com/t5/Windows-d ... d-p/112520

I know this is a very old thread, but I've just noticed the same problem I think since updating to MM 4.1.0.1692.

I installed the latest version yesterday and then noticed on a few tracks when using playback in MM on Windows 8.1. At first I thought it was just an issue with those few tracks, that the files were corrupted in some way, but I noticed it again this morning when I fired up MM to start playing some music - this time the volume was low for the first 25 seconds or so of the first track, then it righted itself; when I restarted the track the volume level was as it should be and it seems to be ok at the moment.

Has anyone else had these issues? I don't know if it's some kind of issue between MM and Windows 8.1?

Only with MM the volume is changing by a ghost hand.
If a play a track, volume is increasing by clicking during surfing with my browser. Decreasing also.
Sometimes it doesn't, sometimes it does
What goes on?