A surplus empty page is often added when printing a number of handout pages from impress. E.g. if the handout layout is 4 slides per page and a number of pages is printed that is a multiple of 4 the additional page appears. This can also be seen in the preview of the printing dialog. This behavior does not depend on whether hidden slides are present or not.
Sounds like a DUP of Bug 31966 - PRINTING: blank page add at end of printed document (although there we talk about 2 slides per page) @reporter: Please feel free to reopen this Bug if you find evidence that we have an independent issue here and if you can contribute required additional information to demonstrate difference to a.m. bug (due to <http://wiki.documentfoundation.org/BugReport> (especially BugReport Details)!) Thank you for your attention! *** This bug has been marked as a duplicate of bug 31966 ***