I have a custom UITextField with a UIImage as a background. Now when I type in a text into this UITextField and the cursor is blinking I get this:
Have you tried setting textField.backgroundColor = [UIColor clearColor]?
You can use a UIImageView for the image and then add a UITextField as a subview with clear background. Just create UIImageView *imageView and UITextField *textField, either programmatically or in the IB. If you go programmatically, use [imageView addSubview:textField]; and set the frame as you like. In the IB, just drop the textField onto the imageView and align it as you like.