Moving a model, smooth in one window drastic in the other.

Hello all.
How do I fix this. I am working in a model in the edit mode.
In one window I can grab it rotate it and work with it. In the second window also user ortho trying to rotate it can move it way out of view. It is not rotating on it’s own point of origin I think.
How did this happen, and how can I fix it?
Advice please?[ATTACH=CONFIG]192813[/ATTACH]
Thank you

Difficult to tell, but the location of the mouse when you start the transformation can greatly affect the result. For instance, if the mouse is close to the center of the window when you hit the ‘R’ key, the rotations can get quite wild, but if the mouse is further from the center, then more subtle movements happen. Also, as you guessed, it helps if the pivot point is correct, so right-click on the object or part of the mesh you want to rotate around, and hit ‘.’ (period) on the numeric keypad to set the item you click on as the center for your rotations.

Thank you for the info on selecting a part and then hitting the period symbol! did not know that.