The scroll function don't work when I'm using my touchpad on my laptop, this is a problem only in firefox and it started after upgrading from firefox 6.

Try to modify the pref ui.trackpoint_hack.enabled on the about:config page from the default value -1 to 0 or 1 to see if that makes the scroll pad work.
Close and restart Firefox after changing the pref.

To open the about:config page, type about:config in the location (address) bar and press the "Enter" key, just like you type the url of a website to open a website.
If you see a warning then you can confirm that you want to access that page.

• Use the Filter bar at to top of the about:config page to locate a preference more easily.
• Preferences that have been modified show as bold (user set).
• Preferences can be reset to the default via the right-click context menu if they are user set
• Preferences can be changed via the right-click context menu: Modify (String or Integer) or Toggle (Boolean)

Now I have tried out the suggested solution, but that did not work. Do you other suggestions to solve the problem?