Can't copy and paste from "popup lightboxes" in Chrome Version 40.0.2214.94 (64-bit)

In recent days I've slowly been losing my mind trying to copy and paste URL's, code snippets and other bits of information. Assuming when I paste and see "old" pasteboard content that I hadn't pressed CMD and C correctly.

But I've pinned it down to only happening in popup light boxes, I disabled all extensions and it's still not working.

Any ideas?