user does not accept relationship even if he does

I haven't explored further to verify but there should be a proper message for this case as can be seen in the array of messages below ('existing_relationship'). This is in user_relationships_ui.module

    'error' => array(
      'too_many_relationships'  => 'You may not create any more relationships to this user.',
      'existing_request'        => 'There is already an earlier %relationship_name request sent to !requestee.',
      'existing_relationship'   => 'There is already an existing %relationship_name relationship with !requestee.',
      'not_accepting_requests'  => 'This user does not accept relationship requests.',
      'self_request'            => 'You may not create a relationship to yourself.',
      'non_existant_user'       => 'This user does not exist.',
      'non_existant_type'       => 'This relationship type does not exist.',
      'unknown_error'           => 'An error has occurred. Please contact the site administrator.',
      'relationship_type_not_set' => 'Please choose the type of relationship.',
    ),

The UI should not let you see the 'request' link again, after you've sent one. The link normally changes to "You have sent a new zzzz request to yyyy (pending requests)" - see screenshot for 'admirer'. Is the link you click something that is custom made?

np, please reopen if the problem is really there.

I had the same thing...my bad...I didn't set all the permissions on the permissions page. Just in case someone else makes my rookie mistake.