After installing Lion, three finger gestures no longer work in the Twitter for Mac app. (I've gotten used to swiping left with three fingers to go "back" after—for example—clicking on a person's avatar to see their timeline.) In the Trackpad System Preferences panel I've disabled three finger drag, and changed "Swipe between full-screen apps", "Mission Control" and "App Exposé" to four fingers to try to eliminate conflicts. But the three finger swipe still doesn't work in Twitter.
Has anyone been able to re-enable three finger gestures in Twitter for Mac? How did you do it?