I was hoping that old command would still work
Before I have you remove and then reinstall IE or upgrade to IE7, lets check some other things like ram usage.
Close all other IE instances except for the one you are using to view this.
Press the Ctrl + Alt + Delete keys at the same time to bring up Windows task manager.
Now select the Performance tab, in the "Physical Memory (K)" section please note what each one is:
Now in the "CPU Usage" section note if the % usage rises and falls a lot or if it just stays steady more or less.
Next, still in the same task manager window select the "Process" tab, look to make sure you have only one instance of IE (IExplorer.exe) running.