Disable changing desktop with scroller

[Freek <freek apollonus net>]

Hi  guys,

I  just bought a new mouse which has "smooth" scrolling wheel (let's
skip commercials :-) ).
The problem is that whenever the background in gnome gets "scroll"
event, it changes desktop. 
And as the wheel is smooth it just starts changing desktops very rapidly
(N times/sec). 

So the question is kinda simple- where and how can I disable changing
desktop with mouse wheel?

Thanks,

May