Right now, there's no feature in the program to do this, but I'm going to add one soon. In the meantime, you can copy the what.xGestures.plist file located in /Library/Preferences/ to another computer or user account to copy all of your xGestures settings.

Every now and then, though usually this is pretty rare, a dialog or a sheet will be recognizable as such, but won't have any way for another program (say xGestures) to see what dialog buttons are in its dialog box and then try to click them. Usually this is made possible using Apple's accessibility API, but sometimes it breaks and then there's no way to click the buttons. As a last ditch effort xGestures will try to send a return or command-period keystroke so that something (anything) will happen, but sometimes that doesn't work either. So far, I personally haven't encountered a dialog box that xGestures couldn't click the buttons on, but I'm sure there's still some out there in the wild, just waiting to annoy someone. Worst case scenario, you'll have to move the cursor to the buttons and click them the old fashioned way.

Make sure you typed in the menu item exactly as it is on the menu itself, capitalization and everything. If it contains an elipses character, be sure to try both three periods and the actual elipses character, typed by holding option and pressing semicolon.