Havent used 1.6.1 yet. But try to look for it through the search bar. If youre using linux (which is friggin awesome and I had Ubuntu 12.10 which is.. THE BEAST ) hit ctrl + h to reveal hidden files (i.e. files starting with a period(.)). Try to enable your pc to display hidden files or something maybe it has the . before the name. Or otherwise they might have scratched the lastlogin file idea and came up with something new :P... If so, just wait around until someone finds it