I am using my own icons for print, email, share.
The print and email buttons appear to duplicate, off register.
Go look here: http://www.bostonsight.org/
It's the worst in Chrome.
What can I do to make the second (duplicate?) image go away?
You've set custom images for the background of the AddThis buttons (See your file boston.css around line 164). These backgrounds are repeating - which is the default for CSS backgrounds. You need to either remove these background declarations or stop them from repeating. More information about backgrounds in CSS is available here: http://coding.smashingmagazine.com/2009/09/02/backgrounds-in-css-everything-you-need-to-know/
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