Catalog scrolling is REALLY fast (Mac)

[Roccobot]

I have a pretty common configuration among Mac users: iMac + Magic Mouse.
When I'm browsing picture miniatures on a catalog, if I scroll up or down with the mouse wheel (which is actually a sensitive area on that mouse), the view moves up or down accordingly but really, really fast: I'm not sure I can explain it properly, but it goes up or down by more than a full screen at once with a minimum touch. My mouse settings are default, except the 'natural scrolling' which is off since I really hate it (but it's the same if I turn it on).
Is there a way to set a lower sensitivity for the mouse wheel scrolling?

Thanks