I have sort of the reverse problem expressed here in this S.O. question
In my case, I (iPhone 4.3 GM) and a tester (iPhone 4.3.1) are seeing the behavior that when we adjust the volume with our finger on the MPVolumeView or with the physical volume switches, the speaker volume overlay is always appearing (see screenshot).
Here is the code where I create the MPVolumeView. I think it is totally generic and standard:
MPVolumeView *volumeView = [[[MPVolumeView alloc] initWithFrame:volumeSlider.bounds] autorelease];
[volumeSlider addSubview:volumeView];
*volumeSlider is simply an outlet to a plain UIView that I put on in IB.
The one other thing I can think of is that in IB, the volumeView view is checked as hidden. Then I unhide it when my audio starts playing (it is an audio streaming app).
Thank you for any help!