Problem using hook_page_title_alter()

Hello,
I am trying to use the hook_page_title_alter() function, and after creating my own module and getting the function to run, I am having trouble actually modifying the title. I tried both receiving the title by reference (&$title) and returning the edited title value.

The one way I was able to get it to work was to change page_title.module line 275 to:
call_user_func_array($function, array(&$title));
This passes the title variable by reference and enables me to edit it using
hook_page_title_alter(&$title)

I'm guessing this could be a bug in the hook implementation of this module, but I may just not know the correct way to use the hook system in this case.

Thanks!