#105 PHP5 + 2.4.7CVS cant use += (-=) with arrays

[V@no]

Hi!
When I try add something to existing value in the array
by using += it kills the array.
example:
[php]
<?php
$a['key'] = 3;
$a['key'] += 2;
print_r($a);
?>
[/php]
the result is:
5
instead of:
Array ( [key] => 5 )