Custom MPVolumeView Thumb Image not vertically centered since iOS 5.1

I'm building an application that needs an MPVolumeView to control the volume. It worked perfectly before iOS 5.1 but since the 5.1 update the thumb image is no longer vertically centered. I tried a few things like changing imagine dimensions, resizing my views (and slider) but nothing seems to work, the thumb is just not vertically centered anymore. The only way i get a centered thumb is if i use the default iOS one. I tried adding a UISlider to another view with the exact min, max and thumb image and that one is centered fine. Here is the code for the MPVolumeView: ``` MPVolumeView *volumeView; volumeView = [[[MPVolumeView alloc] initWithFrame:volumeViewHolder.bounds] autorelease]; [volumeViewHolder addSubview:volumeView]; UIView *volumeViewSlider; for (UIView *view in [volumeView subviews]) { if ([[[view class] description] isEqualToString:@"MPVolumeSlider"]) { volumeViewSlider = view; } } [(UISlider *)volumeViewSlider setThumbImage:sliderHandleIcon forState:UIControlStateNormal]; [(UISlider *)volumeViewSlider setMinimumTrackImage:leftTrackImage forState:UIControlStateNormal]; [(UISlider *)volumeViewSlider setMaximumTrackImage:rightTrackImage forState:UIControlStateNormal]; ``` volumeViewHolder is just a UIView thats 153x33. I put the thumb in green in the screenshot.