I know this is a late answer, but I have the same problem with testing the application for iOS 7.1.
If you install the image in code, it works correctly. Example:
- (void)viewDidLoad {
[super viewDidLoad];
[_segmentedControl setImage:[UIImage imageNamed:@"779-users-toolbar"] forSegmentAtIndex:0];
}
In my project, I have a normal image, as well as @ 2x and @ 3x image versions.
I checked the code in 7.1, xcode 6.1.
8.1, , IB, , 7.1, 8.