A friend of mine has reported a problem whereby his computer is very sluggish when scrolling a web page, I believe, using the scroll wheel.

All used to be OK until about a month ago when he started experienceing this problem. Has anyone any experience of anything of this type? Is there any sort of 'mal-ware' which you've come across which might do this?

He's running Windows ME and connecting via AOL usinf Internet Explorer on a machine which is about 3 years old. It doesn't seem to be site related and as yet I've not determined whether this happens on web pages stored locally on his machine or only when he's actually connected. Nor have I yet checked whether this also happens in Netscape.