Contact support with details of what client you're using and a game or two where this happened? I presume you're talking about live chess, but you don't say so.
chess time
FLYDOGG, sounds like you are having some connection issues.
Do you mind trying some of the suggestions found at the following link for me?
http://support.chess.com/Knowledgebase/Article/View/167/0/my-internet-connection-is-fine---why-am-i-getting-disconnects
I think it'll help solve your problem :)
i consantly lose on time when i have time to play the game cheats me saying i ran out of time when in fact i have more time left to play than the other player who wins on time that some cheating error it knocks my ratings down all the time