I'm too lazy to find a web page that shows this behaviour but if you can give me an URL I can at least see if it happens on my Mac, just to prove that is a general IE problem, FWIW.

IE:mac is kinda slow, and if it's still on the 233Mhz iMac then yes, I can understand how it'd be sluggish. :( Could be worse, my 68030/33 Mac could (and did) spend about a minute loading the Yahoo.com.au front page :)