My app implements a custom segmented control background image using:
// customise the segmented controls
UIImage *segmentSelected = [[UIImage imageNamed:@"segcontrol_sel.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 15, 0, 15)];
UIImage *segmentUnselected = [[UIImage imageNamed:@"segcontrol_uns.png"] resizableImageWithCapInsets:UIEdgeInsetsMake(0, 15, 0, 15)];
UIImage *segmentSelectedUnselected = [UIImage imageNamed:@"segcontrol_sel-uns.png"];
UIImage *segUnselectedSelected = [UIImage imageNamed:@"segcontrol_uns-sel.png"];
UIImage *segmentUnselectedUnselected = [UIImage imageNamed:@"segcontrol_uns-uns.png"];
[[UISegmentedControl appearance] setBackgroundImage:segmentUnselected forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[[UISegmentedControl appearance] setBackgroundImage:segmentUnselected forState:UIControlStateDisabled barMetrics:UIBarMetricsDefault];
[[UISegmentedControl appearance] setBackgroundImage:segmentSelected forState:UIControlStateSelected barMetrics:UIBarMetricsDefault];
[[UISegmentedControl appearance] setDividerImage:segmentUnselectedUnselected forLeftSegmentState:UIControlStateNormal rightSegmentState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[[UISegmentedControl appearance] setDividerImage:segmentSelectedUnselected forLeftSegmentState:UIControlStateSelected rightSegmentState:UIControlStateNormal barMetrics:UIBarMetricsDefault];
[[UISegmentedControl appearance] setDividerImage:segUnselectedSelected forLeftSegmentState:UIControlStateNormal rightSegmentState:UIControlStateSelected barMetrics:UIBarMetricsDefault];
It was perfectly working before I updated to XCode 4.5 and iOS6. Now it's like that: as you can see the background images size were altered. Did any anybody have the same problem? Also some of the background images for some screen look shorter the requested. In one of them for example I have a blank space.
Make sure you name your images with @2x if they're at that resolution.
I had a similar-looking problem which was fixed when I added that.