First things that come to mind: how's your computer doing in general performance wise and which browser are you using? I believe the chess.com interface is a bit heavy to run (for a java app), so if your computer or browser doesn't handle java too well, it could cause some problems.
Also, I'm moving your thread to the Help & Support section, you may get better responses there.
I am having big problems with the live chess application. It often crashes when loading up all the available matches. And it is slow when playing a game, I seem to lose about a second a move compared to my opponent just because of this. I have used other websites as playchess and chesshere, which both run fine and fast, but I have a full membership on here, how come this one is so slow and is there anything that I may be able to do?