Exposed Filter in Embedded View not working

I've looked through the Views issue queue and haven't found much on this; but I cannot seem to get exposed filter inputs to be accepted in a programmatic context.

In the module I'm writing, I want the autocomplete widget on a form to either utilize a pre-defined view display and pass the autocomplete text to the view as an exposed filter input for Node:Title.

According to "Starting Views 2 Documentation" (http://groups.drupal.org/node/10129), it should be as simple as:

<?php
$view->exposed_input['filter_identifier'] = 'filter_value';
?>

But, that didn't work.

Next, I found code in another issue as follows:

<?php
$view->set_exposed_input(array('identifier' => 'title', 'value' => $searchstr));
?>

But, that didn't work either.

Attached is my current "view" object, and a snippet from the module I'm working on. Any help would be greatly appreciated.

From my module:

<?php
/**
 * Looks up ACTIVE products in the system which PERMIT registration.
 * Generates a JSON array for use in autocomplete widgets.
 */
function uc_product_registration_productreference_autocomplete($searchstr) {
  $searchstr = check_plain( $searchstr );

  // see if a view is defined that lists active products
  // in this way, admins can define what products are 'active'
  // based on any criteria they want
  $view = views_get_view('product_registration');
  if ( $view ) {
    // not sure why, but Views doesn't allow me to 
    // pass the display NAME as the ID parameter
    // we'll have to include a DEFAULT view for this.
    $display_id = 'block_1';
    $view->is_cacheable = FALSE;
    $view->set_display($display_id);
    $view->set_exposed_input(array('identifier' => 'title', 'value' => $searchstr));
    $view->build($display_id);
    $view->execute($display_id);
    
    if (!$view->execute()) {
      // there was a problem. 
      print drupal_json(array());
      exit();
    }
    // if the view is defined and we can execute it
    // collect data from here instead of the rest of this function.
  
    $results = array();
    // scan through each result from the view
    // REMEMBER: $result is an OBJECT of type stdClass !!!
    foreach ($view->result AS $obj) {
      // limit the title length to a safe number of characters 
      $title = substr( check_plain($obj->node_title), 0, 42); 
      $index = sprintf("%s [nid: %d]", $title, $obj->nid);
    
      // index the result
      $results[$index] = $title; 
    }
    
    // send data back to the browser and exit.
    print drupal_json($results);
    exit();
  }
...
...
?>