IPhone : Why I got this strange behavior for UIView with gradient background?

I am trying to add gradient layer to a UIView that contains a UILabel.

My UIView implementation:

class ContentView: UIView {
    override init() {
        super.init()
        styleIt()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        styleIt()
    }

    required init(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        styleIt()
    }

    private func styleIt() {
        var gradient = CAGradientLayer()
        gradient.colors = [Utils.Colors.gray_ee.CGColor, Utils.Colors.gray_dd.CGColor]
        gradient.frame = bounds

        layer.insertSublayer(gradient, atIndex: 0)

        layer.borderColor = Utils.Colors.gray_aa.CGColor
        layer.borderWidth = 1

        layer.cornerRadius = 7.0
    }
}

But here is what I got as a result shown in the iPhone 6 iOS Simulator

Only the UIView with cornerRadius is having a strange behavior all other elements in this screenshot are not UIView elements.

I have tried to comment border-related code and radius code, but still same issue.