Hello,
NGUI on Blackberry seems to have similar problems as it does on Windows Phone 8 (multiple touches registering? Not sure.) but unchecking "Use Mouse" doesn't fix the responsiveness. I tend to have to press a button 2 or 3 times to get it to register. I've also unchecked "Use Joystick" and "Use Keyboard". It still functions, it's just the responsiveness that's the issue. EZGUI had similar problems, but changing all the events to "On Press" fixed it (it must use the first event and ignore any extra) but NGUI "On Press" doesn't solve the issue.
Any ideas?