You could possibly try going to launchpad and pressing Command-Left or Command-Right to move through the pages. Then take a trip to System Prefs and have a look under "Trackpad" settings and see if they are all correct. There is a preview of what the action should be with the gestures. Try copying that exactly and make sure your other fingers dont touch the trackpad.
If that doesn't work then please reply and I'll do some research
Hope this helps,