Sometimes how fast you move the mouse can affect how it behaves - if you move it fast, sometimes it can jump over a part. One thing you may try is adjusting the sensitivity slider to see how it affects your results. Just be aware that the more sensitive you make it, the more it can affect drag performance.
You should always be able to use a screen shot pasted into MS Paint.
Now if you can't show because its proprietary, we all understand.
Point being, this should not be a technical limit.