iMac OSX 10.8.4 Volume adjusts by itself I'm certain that this is user-error on my behalf and not an issue with the software or hardware. I've got the latest iMac (2013) and updated my OSX to the most current version of Mountain Lion (10.8.4)

The problem i'm having occurrs in all applications and affects the volume setting. Applications i use and have experienced this issue with:


Spotify
iTunes
Chrome (Youtube, HTML5 Video &amp; Audio, Flash Players)


Sometimes i stream podcasts that have a low default volume  so i like to turn up my OSX Volume to full in order to hear them. However; when i use either the volume slider in my top bar, or the volume keys on my keyboard and adjust the volume beyond around 60% after about 5 seconds playback the volume automatically goes back down to around 60%.

See image:



I've recorded a 15 second Screencast with sound, here is the Screenr.

I've been into System Preferences &gt; Sound  and taken a look around the output settings but i can't see anything that would restrict the volume to this.

Any and all insight to this problem is greatly appreciated! Thank you in advance
Check any third party software relating to sound output management. I'm not talking about apps such as iTunes or Spotify, but rather things such as Soundflower or other apps that modify how sound is output from your system and record system sounds.