Fatal error in product page

Hi,
After upgrading to version 1.5.6.4, i start get an error in product page in admin, when I try to enter to product page I get the following:
Fatal error: Allowed memory size of 67108864 bytes exhausted (tried to allocate 20736 bytes) in /home/xxxxx/public_html/system/library/image.php on line 34

Thanks for help

Any help please?