Thank you for the link to the Drupal forum thread.
As far as I am aware, we have not had any other users report such an issue ('Open Image' button displays blank page which needs to be refreshed in Chrome).
This might somehow be related to the fact that your linkURLs all currently use http://localhost/
Does this happen in other WebKit based browsers, too (Safari and Opera) or just Chrome?
Are you able to have your linkURLs generated using relative paths (rather than absolute in the form http://localhost/) or perhaps just using a leading slash to denote your root directory?
For example:
linkURL="/cars-copy/sites/default/files/2014/03/26/forest-light-900.jpg"
... instead of:
linkURL="http://localhost/cars-copy/sites/default/files/2014/03/26/forest-light-900.jpg"
This may or may not work but might be worth trying to see if it makes a difference. It might turn out to be suitable workaround.
Incidentally, if you leave the linkURL empty, Juicebox will just use the imageURL instead when the 'Open Image' button is clicked.
You say that "As soon as I have the site pre-live I can post here a url so as you and others debug the issue.".
I can't help but think that as soon as you do this (and move away from using 'http://localhost/'), the problem may no longer happen.