[Lynne]

To quote Steve:

Your PHP does not have enough memory allocated to it to complete this operation. Ask your host to increase the 'memory_limit' variable in php.ini to at least 64M.

To temporarily up your limits edit your includes/config.php file and add these lines right under the <?php line:

ini_set('memory_limit', 64 * 1024 * 1024);

Or just increase your memory_limit setting in php.ini to 64M.