Browsers: Internet Explorer Not Responding

Internet Explorer Not Responding

Ok, this is my problem. When I browse the internet I open a new browser window, often I jump from that window to a new one. When I close the second window and return to the first, I find that first window has stopped responding. At the very top of the window it says "Microsoft Internet Explorer (Not Responding)" Windows is always so very helpful in stating the painfully obvious.

The hourglass cursor appears and the window is totally inactive. Sometimes if I wait a minute it will come back to life, other times I have to bring the Task Manager up to shut down the window.

I've already tested my system for spyware/malware/viruses using Norton Anti-Virus, Ad-Aware, Spyware Terminator, and Trend Micro's online scanner, none of them found anything serious.

I'm using:
Windows XP Media Center edition + Service Pack 2 build 2600
+ Internet Explorer 6.0.2900.2180 on a Dell Dimension E521.

Any and all help will be greatly appreciated, thanks!