I'm constantly having trouble pulling dimensions between to lines or accurately selecting a line while dimensioning. It seems as though no matter how accurate I try to be when clicking on a line it's almost random as to whether it selects the line or not. This is most often a problem when selecting one line and then trying to select a parallel line to draw a vertical or horizontal dimension. Is there any way to turn the selection sensitivity down so I'm not constantly deleting bad dimensions and redrawing.

Thanks