javascript execution

There is no way you can trace updatepanel. Only thing you can do is create a new page without grid and check by creating a sample where you do the same thing and see if it works

any way to find out why the event is not getting hit

As I told you before you. You are using Thirdparty grid. And it may be possible that that grid control might not be compliant with updatepanel and it might be breaking normal functionality.

It may be possible it is breaking in IE. So I would suggest try out on a different test page and see if it works without that grid on the page. Then you will know the exact problem