NGUI - OnPress Trigger is not working in IOS Devices

Hi. I have been working on a racing game and I have used a Race Button and OnPress Trigger I am performing some action. like setting motorInput to 1 and OnRelease() I am setting it to 0. And it’s working just fine on Android n Windows Phone 8 Devices but on IOS OnPress() Trigger is working like OnClick(). It release it automatically after pressing it.
Any body who has encountered this problem?

i have the same question.
The collision worked fine on the game view in unity, but it does not work on android and ios.

if u find the way to fix it, plz tell me, thanks