onBrowserEvent doesn't work after the application is deployed

[inter]

I implemented onBrowserevent for my customize AbstractCell. It's working perfectly when I tested in development mode. For example, if I click on the cell, Window.alert is popped up and says 'clicked'. But, after deploying it to the app engine, it's not working anymore. When I click on the cell, it doesn't seem to respond anymore. Anyone has had the same problem before?