Skype problem with sound?

We are just wondering what could be the problem as whenever my fiance and I talk her volume is really low, then all of a sudden it will go high for no reason, the low for no reason. Then if she brings up a webpage theres a screeching noise. She has bought new head phones, a new mic etc...still no difference. A new USB, no difference. Her internet speed is fast. We have checked the microphone levels on the PS and they are fine and checked them on skype. Dont know what else to do as the problem is at her end not mine. Her camera goes off and on oftern too. She has plenty of memory space on her PC. She can hear and see me just fine.

Any help would be appreciated.

 

Is that something that started recently? I believe that Skype uses Flash Player, and I know the latest Flash Player has various audio (and other) problems. Maybe reverting to an earlier Flash Player version may solve the problem? (See http://forums.adobe.com/thread/1022066).