right-click menu does not appear in Firefox (SmartGWT)

[yi sun]

I'm using SmartGWT, not sure if this is the right place to ask this question.

I have a simple listgrid with a recordClickHandler. what I'm trying to do is to display a popup menu when user right clicks the record. This works fine with IE8,Chrome and Safari but I just can't get it work with Fireforx. In Firefox, when I right click on the record, the Windows popup menu appears instead of my own popup menu. I tried to add event.cancel() but it doesn't solve the problem. Please could anyone here tell me where the problem is? Thanks.