Out of memory, wp-includes/media.php on line 254, but put 256M

Hi everybody,

Hope i ll find somebody who can help me a little.

My problem :
When i upload an image, i got this message error “Fatal error: Out of memory (allocated 61341696) (tried to allocate 13824 bytes) in /homepages/15/********/*****/*******/*****/wp-includes/media.php on line 254“
It upload the image, but i don’t have the different size (thumbnail, medium, and large). So, when i integrate the image in a post, it s a full size.

My config :
wordpress 3.2.1
PHP version 5.2.17
php.ini
-> post_max_size = 256M
-> upload_max_filesize = 256M
defaut-constants.php

if ( !defined('WP_MEMORY_LIMIT') ) {
		if( is_multisite() ) {
			define('WP_MEMORY_LIMIT', '256M');
		} else {
			define('WP_MEMORY_LIMIT', '256M');
		}
	}

	if ( ! defined( 'WP_MAX_MEMORY_LIMIT' ) ) {
		define( 'WP_MAX_MEMORY_LIMIT', '256M' );
	}

I don’t understand why this error occured. Worked fine before. Can it be because of a corrupted image? My host?

If somebody knows how to resolve this, thank you for helping me.

dY00Yb