with fresh install of windows 7 touch pad scroll function didn't work.
Installed 64 bit synaptic touch pad drivers. At first it worked fine, scroll was fixed but sometimes after rebooting the touch pad did not work. If I attached a USB mouse that would work though. Eventually touch pad didn't work after every reboot.
Removed drivers, touch pad worked again but without scroll function.
Found dell synaptic drivers from a later model laptop that was sold with vista 64. They were only available for 32 windows for my laptop model.
Anyway. Think its fixed.
Hope this helps someone else