You should rise the memory limit on our server. This can be set via the php.ini file editing the following line:
memory_limit = 00M ; Maximum amount of memory a script may consume (00MB)
You may double the current value.
Also you may check the following URLs:
http://codex.wordpress.org/Finding_server_info
http://www.wampserver.com/phorum/read.php?f=2&i=16758&t=16742
Once the above value is changes restart the Apache server and the issue should be resolved.
You may need to increase the memory available to PHP. If necessary, talk with your host.
Two methods for increasing the amount of memory a PHP script may consume
If you have access to your PHP.ini file, change the line in PHP.ini If your line shows 8M try 16M:
memory_limit = 8M ; Maximum amount of memory a script may consume (8MB)
If you don’t have access to PHP.ini try adding this to an .htaccess file:
php_value memory_limit 16M
