Ruler (bind-key 'k') not functioning as desired

Dear All,

It may be a silly question. But the issue is creating a lot of problem for me.

I want to draw the ruler from 'x' point to 'y' point orthogonal.The ruler should begin at 'x' and end exactly at 'y'

I draw the ruler like:-

                           1) Press button 'k'

                           2) Zoom in   ( hiZoomIn() ) to the desired point ( x) location by clicking Right Mouse Botton ( for getting the exacr point fine ZOOM-IN)

                           3) Then  press Left Mouse botton at point 'x'

                          4) Then I press Zoom-Out in the Tool Bar (Course Zoom-Out)

                         5)   Zoom in   ( hiZoomIn() ) to the desired point ( x) location by clicking Right Mouse Botton ( for getting the exacr point fine ZOOM-IN)   

                         6) Then  pressRight Mouse botton at point 'y'   

This works fine for me. But at times I don't know what happens, while doing zoom-in using Mouse ( when I press Right Mouse botton) the Ruler gets marked.

Then I have to close icfb ( IC5141) and restart it. Then things work fine.

Could anybody please tell why it is happening so  and what should be done to avoid it.

Kind Regads,