A while back I purchased a new Comp M - XD on sale; I had no immediate use for it but the price was good and I knew I would use it eventually.

It has been sitting in the box ever since. I finally have gotten around to think about mounting it on my AR so I took it out of the box and installed the battery and turned it on.

I set it down on a table top and sighted the red dot on a spot on the wall about 15 feet away.

My eyes were approximately 12" - 14" from the rear of the sight.

I noticed that as I move my head up and down and from side to side the red dot moves. i.e. it does not stay put on the spot on the wall.

The amount of movement of the dot appears to be related to the amount of movement of my head.

At the extreme it appears the dot is moving almost a full inch.

I am a novice when it comes to scopes and red dot sights and technical issues such as parallax.

However it seems to me that the concept of "parallax free" implies that the dot should remain fixed over the spot on the wall regardless of where my eyes are with respect to the sight.

Am I misunderstanding how the sight should behave or is it not working properly?

Thanks!

Yep what troy says!  It is kinda weird once you get it mounted to be able to move the dot around and still hit the target.  

I got the same effect with my hakko.  The guys as the range were looking at me kinda weird when I was moving the gun around and shooting.  LOL.

sound good, thanks!

Got to remember to lock the adjustment screws in place.  I was shooting today and it started shifting, checked the co-witness and it had shifted.  Tightened everything down and then I was GTG.