I'm resurrecting a bit of an older post here but I think it is the best option...
I have just run into the same issue using the 2.5 version of the Zepher template and using the links in the core login module.Fatal error: Call to a member function init() on a non-object in ...snip...templates\rt_zephyr\html\com_users\reset\default.php on line 18
I have followed the direction on this page and in the linked thread to use the default php pages from the core as listed above and this has in fact fixed my problems, but I'm guessing it may be a bug in the template and would be worth fixing or at the very least if someone searches as I did and finds this thread they have a course of action that could work for them rather than an unresolved issue!
I had to replace the default files for login, logout, registration, remind and reset plus the extras in reset and login get all the functionality back.
Hope this helps!
Jay