The new IE7 Phishing Filter evaluates an entire Web page when the page is opened. If a page contains a number of frames, the Phishing Filter may prevent it from loading. One example we have seen was a web based video conference using streaming QuickTime. The page never loaded with the Phishing Filter enabled. On Dec 12, 2006, Microsoft released an update to Internet Explorer 7. The update is designed to resolve slowdowns for Web pages containing a number of frames.
See these Install Phishing Filter Update steps from the How To Install Internet Explorer 7 for Windows XP. They are written for College Enterprise computers that are using Windows XP Service Pack 2.