I had the profile view problem too.
The S5 userblock conflicts with the profile pages because both use the variable {USERNAME} in different ways.
I used the below to fix it BUT I don't use the S5 userblock so I don't know if it stops it from working.
OPEN: .../vertex/vertex_blocks/vertex_blocks.php
FIND:
// Assign specific vars
$template->assign_vars(array('USERNAME_FULL' => get_username_string('full', $user_id,
$username), 'USERNAME' => get_username_string('username', $user_id, $username), ));
REPLACE WITH:
// Assign specific vars
$template->assign_vars(array('S5_USERNAME_FULL' => get_username_string('full', $user_id,
$username), 'S5_USERNAME' => get_username_string('username', $user_id, $username), ));