Just a little simple tutorial about how to solve a very stupid problem.
SL hands hate animations. Depending on the animations on your AO or places you'll sit at, your fingers can get stuck. It will then appear as appart from each other and your nails or any hand jewelry won't fit anymore.
How to solve the problem ?
A "stop all animation" won't solve it. What you need to do is to play an animation that will move your hands too. I've been searching for such an animation on the marketplace that is available for free so I can give out a name but unfortunately, it is hard to find out there. So check out animations stores around SL, as long as the animation changes the position of your hands & fingers, it will work.