My PDF files open in the same page when I click an image in lightbox jquery iframe

Q: I've just bought the Visual Light Box earlier today and very impressed.
I just have one small query you may have an answer for.
I have a finished a gallery, all good to go embedded in an existing page and have set links for each image to a series of PDF files, but although I have set 'target="_blank" in the the html, the PDF's still open in existing browser window and I cant think of any reason as to why?

A: I couldn't repeat this problem. I specified a link in the following way:

<a href="" target="_blank">Click here to open PDF file</a>

If problem will persist, please send us your project file (.vislb), so we can check it.