Hey DigitMus,
Thanks for the question. With the introduction of Lion, the swipe to navigate default gesture changed to a two-finger scroll. System Preferences > Trackpad provides three options for "Swipe between pages":
- Scroll left or right with two fingers
- Swipe with three fingers
- Swipe with two or three fingers
You'll want to make sure this preference is set as you wish, and checked to be enabled. For more information, see these resources:
Mac Basics: Multi-Touch gestures
http://support.apple.com/kb/HT4721
Apple - Use your fingers to use your Mac in OS X Mountain Lion.
http://www.apple.com/osx/what-is/gestures.html#gallery-gestures-swipe
Swipe to navigate – Web pages in Safari, documents in Preview and more, just like thumbing a page in a book. Note: If there is horizontal content to scroll, this gesture will first scrolls to the end of content and then it will move to the next page.
- Magic Trackpad – A horizontal two finger swipe will show the next or previous page. Tip: Once you pass the rubber-band threshold, lift your fingers to change page. Also you can flick your fingers at the end of the swipe for momentum.
Thanks,
Matt M.