Here's a little more information for Part 1, as I don't think I really explained myself.

For example:
<?php
// Let $fp1 and $fp2 be resources

// Array creation - Method #1
$resarray = array();
$resarray[$fp1] = 'fp1';
$resarray[$fp2] = 'fp2';

// Method #2
$resarray2 = array(
    $fp1 => 'fp1',
    $fp2 => 'fp2');
?>

For Method #1, PHP behaves as expected. The resource is casted to an interger and the array is populated.

For Method #2, PHP does not behave as I would expect. The resource is not casted, no error is thrown and the array is not populated.

This is demonstrated in the Reproduce Code section.

I'm going to re-paste the Reproduce Code section, as it is rather confusing.

Part 1;
-------
Inconsistant behaviour between different methods of array creation.

<?php
// Create two resources
$fp1 = fsockopen("www.example.com", 80, $errno, $errstr, 30);
$fp2 = fsockopen("www.example.com", 80, $errno, $errstr, 30);

// Add them to an array with two different methods
$resarray = array(); $resarray[$fp1] = 'fp1';
$resarray2 = array($fp1 => 'fp1', $fp2 => 'fp2');

// Show the result
echo "resources: first method:\n";
var_dump($resarray);
echo "resources: second method:\n";
var_dump($resarray2);
?>

With Method #1 there is no problem.
With Method #2 no error is thrown, and the array is not populated.


Part 2;
-------
Failure of an object to cast itself to an interger or string. With the second method, failure to produce an error.

<?php
// Create a sample object
class id_obj { var $_id; function id_obj($id) { $this->_id = $id; } }

// Create two new instances
$id1 = new id_obj(1);
$id2 = new id_obj(2);

// Add them to an array with two different methods described above
$array = array(); $array[$id1] = 'foo';
$array2 = array ($id1 => 'id1', $id2 => 'id2');

// Check the results
echo "objects: first method:\n";
var_dump($array);
echo "objects: second method:\n";
var_dump($array2);
?>

In Method #1, an error is thrown (Illegal offset type). The array is not populated.

In Method #2, no error is thrown and the array is not populated.

This bug has been fixed in CVS.

Snapshots of the sources are packaged every three hours; this change
will be in the next snapshot. You can grab the snapshot at
http://snaps.php.net/.
 
Thank you for the report, and for helping us make PHP better.

$a = array($objectvar => 'value');
$b = array($arrayvar => 'value');
$c = array($resourcevar => 'value');

Will now throw an E_WARNING "Illegal offset type" just like:

$a[$objectvar] = 'value';
$b[$arrayvar] = 'value';

already do.



$c[$resourcevar] = 'value'; 

will continue to work (for backwards compatability), however it will now throw an E_WARNING "Resource ID#X used as offset, casting to integer (X)" to strongly discourage this behavior.  

If this is a genuinely desired/used feature, then the error can be supressed using the standard @ operator or (preferrably) by manually casting the resource to an int:

@$c[$resourcevar] = 'value';
$c[(int)$resourcevar] = 'value';