This is a bug, actually an omission on our part.
We recently put in this feature to set the 'event' variable within the scope of all widget events. It looks like this was missed for the grid. So 'event' is simply not defined in the grid event handlers. It is on other widgets.
So what happens then is that your code is picking up on IE's 'window.event', where we haven't defined anything.
That your function is running asynchronously is not the problem. The 'event' variable (if we had defined it properly) would simply copied into the scope of the function you're passing to 'setTimeout', due to the concept of 'closures' in JavaScript:
https://developer.mozilla.org/en-US/doc ... e/Closures
So, your code is perfectly fine and would/should work, assuming we set 'event' properly in the grid event handlers. We'll fix that up.
Meanwhile, unfort., I don't think you have any way to grab it in FireFox, due to it not having a global event property like IE. This is why we implemented this feature to begin with, but apparently not 100% complete.
Sorry for the confusion.