I lost my game against Scorpionsting after he didn't made a move in more than an hour (90' game) and he runned out of time. How is that possible. Can you win a game just by not making your move?

the game says it was abandoned by you. perhaps you disconnected and considered you abandoned the game. you can always try to report the "error" to chess.com staff and have them check it out for you.

Looks like your opponent made the last move.

http://www.chess.com/livechess/game.html?id=5889028

I would guess that you were disconnected and did not realize it.

 No, I saw on my screen clearly my move as the last one and HIS time was running; but when I relogged in  my move was disappeared. I couldn't also reach my opponent by chat: it didn't worked anymore.

As suggested in post #2. You can report a bug here.

 Thank you, TadDude