Looking at the "/user/view.php" file in the latest 1.8+ (April 14, 2007), I noticed that you have an English error message hard-corded into the file.
I would suggest making this into a $string that can be handled by the language packs.
"You can not view the profile of this user"
// make sure user can view this student's profile
if ($USER->id != $user->id
&& !has_capability('moodle/user:viewdetails', $coursecontext)
&& !has_capability('moodle/user:viewdetails', $usercontext))