problem downloading

Hi, using Safari I tried to download a program from Adobe. Instead of my download folder popping up I got a black screen in the browser. Tried again at a few other sites
like Version Tracker to see if that was a one off but no soap...same black screen. Tried a few more and still the same story. Then tried Firefox, Chrome and Opera and the new
Safari which I'd downloaded in the interim. Same thing. Recently I'd reinstalled Snow Leopard and fixed disc privileges and everything was running smoothly...even ran an fsck.. Any ideas please. Thanks.
The download folder is the default in preferences.
Oh, and ran clamx and found some email viruses which I deleted but I don't believe
they had any bearing as the problem remained.


iMac 2.66 Core Duo Snow Leopard