Mountain Lion and video chat: video/audio disturbances and disruptions

Hi!

I'm having big problems video chatting with skype since upgrading to mountain lion a couple of months back. There's video and audio disturbances and disruptions, the audio is delayed and video quality is terribly bad. All this makes it impossible to video chat. Also calling landlines and mobile phones is impossible due to disturabnces. Facetime is not an option as my other friends are windows users.

I even made a clean install of mountain lion! That didn't change anything. Then I tried some other providers. However I had the same issues with oovoo and google talk. Can anyone help me to fix this problem. I have a 2 year old MacBook Pro 15". 4gb ram, intel i5 2,5 ghz. So I shouldn't have these problems, right!

Thanks a lot!