Note: "volume adjustment bar" refers to the rectangular bar that can be clicked and dragged horizontally to adjust the users' system's volume level up or down.
Expected behavior: The user should be able to adjust system volume by clicking anywhere on the volume adjustment bar and moving their mouse/trackpad left or right.
Actual behavior: When attempting to click the volume adjustment bar, the bar can only be clicked, it appears, from the top 50% of the bar itself to 50% above the bar. It looks like the bar's selection area has been "pushed up" half of the bar's vertical length. In other words, rather than clicking the actual adjustment bar to adjust system volume, the user can only click the top vertical 50% of the bar itself and another 50% of the bar's total height above the bar itself to adjust volume.
See the attached screenshot for a visual depiction of the explained behavior.
thank you for your report - I could not reproduce in 12.04 - please reopen if this issue still exists in Ubuntu 12.04