You'll need to specifically load the userinfo for the target userid:
Code:
$profile_userinfo = verify_id('user', $userid, 1, 1);
.... where $userid is the userid which owns the profile you are looking at. Don't know how you are deriving that, but you should have it somewhere in your code.
Also, note the $profile_userinfo instead of $userinfo. It's generally a good idea not to mess with $userinfo, as this can have unforeseen consequences!
-- hugh