What you get might be driver dependent, but mine has for tabs, with the last one named 'Scrollwheel' and offering the possibility to scroll 1,2,3,4,... lines or a page at a time. If it's the same with you, it might be set to 'page'. Play a little bit with it, and let us know if it works.
Hope this helps.
Does anyone know of a way in an Excell Spreadsheet to use the mouse wheel to move the cell up or down one cell at a time rather than scrolling the whole page using the wheel?