OnMouseXXX series API don't work in webstream sometimes (417975)

Hi,
I met one very strange problem here.
I use onmousedown to detect mouse click on one mesh with collider. It works fine in Editor and in most time, it also works in kinds of web browsers.
But sometime, it will just not work, and after this happened, it will never work again in this web browser. Like what I used now Maxthon 2.5.9.
It used to work in my maxthon, just once it doesn’t work, now everytime, it will not trigger onmousedown event, and I also tried onmouseover, etc, same result.
Meanwhile, the same .unity3d file just works fine on other web browers on my machine, like IE7, firefox, etc.
Does anyone have similar case with me? Pls give some help I have stuck here a long time.
Thanks a lot!

further info.
I wrote one simple script using raycast to simulate onmousedown, it works in Editor.
In webbrower, the raycast is ok, the problem is Input.GetMouseButtonDown(0) has no correct response as in Editor.
This is called update();
Any comments?

OK, now confirmed even GetMouseButton not workable.
I guess it should be one bug now.