One of my kitchen spot (not halogen) bulbs has blown. When I unscrewed it to remove only the glass bulb part came out leaving the metal screw fitment which I'm having trouble removing. Any ideas how I remove it? This happened to another spot a couple of months ago but I did manage to unscrew it by hand, now I haven't been so lucky. Is this a common problem or does it indicate a problem with the lights? Hope someone can help me, thanks.