Also I should add that adding any additional images works fine, uploading image-name_1.jpg shows the extra image on the page and clicking that thumbnail zooms the extra image into the lightbox zoom function.

Also using the firebug plugin and changing the code on the page to the correct image url allows everything to work fine as well.

So simply, where is my site getting this new link code from with the /large/ and the _LRG.jpg additions to the URL?