Two things:
The following bit put into spoiler tags because it was plain wrong.
Spoiler:
These dlls have only been successfully tested with Calibre 2.7, and they definitely do not work with 2.8. So install Calibre 2.7 first (from
http://download.calibre-ebook.com/2.7.0/). I assume the problem is because we are patching Calibre, and there is a version specific, binary dependency between Calibre and the dlls. This should be sorted once the dlls are part of the official Calibre build and install. For now, I can only support Calibre 2.7. You are welcome to try it with earlier versions to see if they work, and report back here. I have tested already with Calibre 2.8, and it definitely does NOT work.
There seems to a be a bug in the Linux code whereby two idevices are detected when only one is connected. I have just posted a new set of dlls with a fix to ignore idevices without a valid product_id. This bug caught me out today - the code was connecting fine yesterday to my IPad, but not today, yet NOTHING had changed. Sigh. The joys of programming.