Not really ... as I said, I can't get it to fail . You realize it only works when in the process of uploading files (it won't work on files that are already on the server), right? And I'm assuming that you did "activate" it.
I don't mean to be patronizing with those last remarks; I'm just trying to figure out why it isn't working for you.
The only other thing that I can think of is if it is somehow conflicting with another plugin you have installed (I have seen that happen with other plugins before).