livemocha.com- i'm having problems with audio and video functions

Hi, my name is Ruthie, a passionate language learner:) Recently I've been experiencing problems viewing video clips and doing audio recordings on Livemocha.com. I don't have any problem viewing vidos on line, nor communicating with my microphone on skype, for example. Livemocha is the only website where I suddenly cannot enjoy either of the above functions. They have advised me to disable an element called pepflash.dll but I don't know how to go about it, I'm not exactly an expert on handling such problems, nor did I find such an advice here. Your advice to help me out of this situation and enable me to help other memebers and go on with my studies will be most most appreciated. Tks and have a good day!