Volume Box wont go away

While playing World of Warcraft my monitor brings up the volume box from no where. I click the button on the side to make it gone, thinking nothing of it. However when i hit the button, it went and then CAME BACK =S. Had this monitor for a number of years, no issues. We've tried unplugging the monitor, resetting the computer...nothings working. And something is making the volume go to zero cause i will hit the UP volume button and itll be resisted and dropped back to zero :S.