Rotating around random point?

Using Ignition 7.8 on Windows 7.

Sometimes when I close a property dialog box, the selected object will jump to a new position on the screen and pressing ctrl-Z will undo the change I made to the property, but will not move the item back to its original spot.

The last time this happened I was working with a grouped object (a couple of ellipses that I made to look like fan blades) and bound their angle property to a simple equation


so once a second my fan blade position changes by changing the angle of the grouped object. It was working fine until it randomly jumped on my screen after closing the property dialog box. Now it rotates around some random point outside my design area.

I can delete and remake them easily enough, but in the event that this happens to something I cannot easily recreate a) how can I find and change the point it is rotating around and b) how can I get my objects to stop jumping around when I close the property dialog box? It isn’t every time, and I can find no rhyme or reason as so what I do that would cause this to happen.