Pluto, the lo(a)st planet

In March, i imaged Pluto with Celestron C14 telescope and SBIG ST9XE camera. Where is Pluto in this image? I have attached a chart here (click the image) and you can find it in this crowded star field.

This chart is from TheSkyX Pro which is a premium software used for planning and controlling all modern observatory equipment but i noticed the position of Pluto is a bit different than marked in this chart. Have no clue why it is so.