Not sure why you are seeing that issue. Here's the template that I use with the KoboTouch and KoboTouchExtended driver (it needs to be entered separately for both).
Code:
Elib/{author_sort:sublist(0,1,&)}/{title} - {authors:sublist(0,1,&)}
The sublist bit just limits the author_sort and author to the first name in the list to keep path lengths to a reasonable level.