Stock chart - alignment of markers

Hi,

I have been having a recurrent problem with the alignment of markers in a stock chart. I am using this chart type to show a point estimate and 95% confidence intervals. However, both the point estimate marker and the bar ends often look a bit off-centre - it's subtle, but does look odd when magnified as part of a Powerpoint presentation.

I have attached an example.

Does anyone know how this can be fixed?

Many thanks

M