Try this category. For me it is working for all iOS.
- (void)setRoundedBorder:(float) radius borderWidth:(float)borderWidth color:(UIColor*)color
{
CALayer * l = [self layer];
[l setMasksToBounds:YES];
[l setCornerRadius:radius];
// You can even add a border
[l setBorderWidth:borderWidth];
[l setBorderColor:[color CGColor]];
}