In reply to Little Brew:
Clicking might mean you've damaged the nail bed... it will either grow out, or it wont... funny thing the body.
It was a cause of contrversy moons ago, the whole calcium- nails-zinc thing, but it is now generally agreed that white flecks or ridges in nails are generally a sign of zinc deficiency (nails contain very little calcium).
If this is the case, then eat more zinc containing foods like meat, eggs and my favorite, cheese (esp. stuff like stilton, wensleydale, etc).
You might also be needing iron. As this can cause bittle nails, so get chomping on the liver and cabbage... mmmm, nice. That and vitamin C helps boost iron uptake.