When viewing the Participants list in any course or via Site Administration, users are shown with User Picture, First Name/Last Name, City/Town, Country, Last access, Select.
When any user is selected the profile overview tab shows (if not hidden from the user) City/town, Email, Courses, Last access, Roles. However, except where Country is set to be a hidden field,
the City/town line ($location in user/view.php) should including the country field thus: City/town: Perth, Australia.
Problem appears to stem from a failure of the function call $countries = get_list_of_countries(); in same file.
Thread http://moodle.org/mod/forum/discuss.php?d=99362 refers.
To see problem click on your own profile link in Moodle forums on 1.9.1 (may also apply to 1.9 - uncertain).