MacBook Pro turns off instantly, charger sparkles.
MB Pro (Early 2011) turns off instantly if I move my charger cable or touch magnetic DC connector (L-type). I can also hear connector sparkle, when moving it. It started happening recently and now it's getting on my nerves, especially if I forget to save a project (because I would have to start all over again). I've read a lot of topics on this problem, but haven't found the exact circumstances.
It would be grateful if somebody explained me the reason and suggested a solution for this issue.
MacBook Pro, Mac OS X (10.7.5)