tons of static on the line with a new Mac

[terraform]

Hi all ..I just bought a new macPro Desktop 2.8ghz quad core intel Zeon and the magic Jack works but has tons of static now, I can barely hear anybody.. It worked fine in my Intel Core 2 duo mac mini before I switched. i tried the mac upgrade and reformatting the icon/drive, pulling the jack out, etc. ..any ideas greatly appreciated! Running Snow Leopard 10.6.4