Mouse annoyance

[kestrel1]

I use my mouse's scroll wheel to scroll whilst using the Internet. The only problem is that if I want to scroll back up a page it won't scroll up, but send me back to the previous page as if I had used the back button. I expect this is easily fixed, but I couldn't find anything in the mouse configuration unless I missed it. This is always possible.
I am using Fedora 9 & a Gnome desktop.
Cheers