QWT: Problem selecting points on a graph

Hey,

I am using qwt for plotting graphs. But when I am trying to select any point on the graph using mouse, either some other point is getting selected or nothing is selected. I have referred to the event filter example. Why is it that it is working fine there but in my code it isn’t? Is there some problem with the axis scales?

Any immediate help regarding this would be highly appreciated.

Thanks in advance.