I agree it is bad practice to do that -- I actually found it in error. I was checking a pop up message down there from one of our apps, and happened to accidently select the firefox little "All downloads complete" window that appears for about 3 seconds in the process which froze both apps.
Kinda got diverted into figuring out how I was freezing TC, and figured out that was it.
I can't pick a property - If I move the target to the window at the moment it appears, it will never recognize the object at all - it just freezes.
I think the problem is that before TC can actually get all of the info from the little window, it goes away while it's still collecting data.