I'm a brand-new widow, trying to do things I have not done before, and would appreciate your help. The new u-shaped fluorescent bulbs I bought to replace the fading ones in my kitchen ceiling lamp are the same brand and model number as the previous ones. I inserted the prongs into the plug end of the fixture, and pressed the body of the bulb into the u-shaped metal clip which should support it at the other end of the fixture. But they were just a little too loose to stay in place. (Picture a zillion glass fragments on my kitchen floor.) Should I try to tighten the metal clip by squeezing with pliers? (Before inserting new bulbs.) Do I need a new fixture? What would you recommend? Is this a common problem? Thanks for your help.