Possible bug in array_diff() php v4.4.0 or at least some odd behavior

I have two arrays: $faqDataPost: array 1 =>

    array
      'faq_order' => '1'
      'faq_question' => 'What is the air speed of a fully laden swallow?'
      'show_question' => '1'
      'faq_answer' => 'African or European?'

3 =>

    array
      'faq_order' => '2'
      'faq_question' => 'Where is our shrubbery?'
      'show_question' => '1'
      'faq_answer' => 'Nee! Nee!'

4 =>

    array
      'faq_order' => '3'
      'faq_question' => 'Where is Lancelot?'
      'show_question' => '1'
      'faq_answer' => 'We eat and drink and dance a lot.'

$faqDataDB: array 1 =>

    array
      'faq_data_id' => '1'
      'faq_question' => 'What is the air speed of a fully laden swallow?'
      'faq_answer' => 'African or European?'
      'faq_order' => '1'
      'show_question' => '0'

3 =>

    array
      'faq_data_id' => '3'
      'faq_question' => 'Where is our shrubbery?'
      'faq_answer' => 'Nee! Nee!'
      'faq_order' => '2'
      'show_question' => '0'

4 =>

    array
      'faq_data_id' => '4'
      'faq_question' => 'Where is Lancelot?'
      'faq_answer' => 'We eat and drink and dance a lot.'
      'faq_order' => '3'
      'show_question' => '0'

/************************************************************/ and this code(sorry the wrap is a bit off): print'<br />$faqDataPost:<br />';var_dump($faqDataPost); print'<br />$faqDataDB:<br />';var_dump($faqDataDB); // Get the changed data... // foreach($faqDataPost as $key => $r) { unset($faqDataDB[$key]['faq_data_id']); $r['show_question'] = isset($r['show_question']) ? $r['show_question'] : 0; print'<br />$r<br />';var_dump($r); print'<br />DB<br />';var_dump($faqDataDB[$key]); if((string)$r['show_question'] !== (string)$faqDataDB[$key]['show_question']) { print "<br />Does Not Match. Should show up in diff</br />"; } $faqDataInsert[$key] = array_diff($r, $faqDataDB[$key]); print'<br />diff<br/><pre>';print_r($faqDataInsert[$key]);print'</pre>'; } /************************************************************/ and these results: $r array 'faq_order' => '1' 'faq_question' => 'What is the air speed of a fully laiden swallow?' 'show_question' => '1' 'faq_answer' => 'African or European?' DB array 'faq_question' => 'What is the air speed of a fully laiden swallow?' 'faq_answer' => 'African or European?' 'faq_order' => '1' 'show_question' => '0' Does Not Match. Should show up in diff diff Array ( ) $r array 'faq_order' => '2' 'faq_question' => 'Where is our shrubbery?' 'show_question' => '1' 'faq_answer' => 'Nee! Nee!' DB array 'faq_question' => 'Where is our shrubbery?' 'faq_answer' => 'Nee! Nee!' 'faq_order' => '2' 'show_question' => '0' Does Not Match. Should show up in diff diff Array (

    [show_question] => 1

) $r array 'faq_order' => '3' 'faq_question' => 'Where is Lancealot?' 'show_question' => '1' 'faq_answer' => 'We eat and drink and dance a lot.' DB array 'faq_question' => 'Where is Lancealot?' 'faq_answer' => 'We eat and drink and dance a lot.' 'faq_order' => '3' 'show_question' => '0' Does Not Match. Should show up in diff diff Array (

    [show_question] => 1

) /**************************************************************/ The problem is that in the first loop through the arrays, array_diff() doesn't pick up that ['show_question'] is different, although it does pick it up in the following loops. The interesting bit is that arra_diff_assoc() DOES pick up the difference in the first loop. Both arrays are built in foreach() statements and I can't see any difference between the first sub array and subsequent sub arrays that would cause array_diff() to miss the diference in the first one. If I change any of the other values in the first sub array, array_diff() will pick those up fine, just not the ['show_question'] part. I'm going to use array_diff_assoc(0 for this right now because it works and that what matters, but does anyone know why I'm having this problem with array_diff()? Can you see something that I'm missing? Thanks! Ed