web browsers keep downloading site intro clips

this seems to happen on the Apple site mostly. If I navigate to the Quicktime page at Apple, the page opens VERY briefly, my browser (Safari + Firefox) downloads the intro GIF (and or Quicktime mov) to my desktop, then returns to the web page or site I was on before the Quicktime page. The same thing happened on the www.apple.com/imac page.
any suggestions, or advise would be greatly appreciated.

update: I figured it out. even though I had Speed Download "disabled" the plug ins were still intercepting some web site content. I disabled ALL the SD plug ins through the SD prefs, and Safari works properly now.