jit.suckah question/bug??

so I am using suckah for the first time in a long while and I am probably just misunderstanding something...

I expected the following behaviour:
place the jit.suckah over anything and a mouse-down will give the the rgb value of that pixel. If I move my mouse inside suckah while it is still down, the values get updated. If I move outside the suckah perimeter, I shouldn't get any more values.

This is what I get:
As long as I click on the suckah and don't let go, my values get updated!! Even when I leave the Max window and drag over something on my desktop!!!

Is that the normal behaviour???
Am I making sense??

here is a quick test patch (for both Max 5 and 4.6). I only want to be able to track the color within the rectangle and nothing else.

Thanks for any insight.