Hi.
I hate when this happens. It's not a collective access specific problem. Try increasing the memory limit in PHP.
Locate the php.ini file used by your web server. You can click the "more information" link on Drupal's status page's PHP section. which shows the phpinfo() page. Locate the Configuration File (php.ini) Path row on that page. During installation Drupal checks the PHP Memory Limit, and if it is less than 64M, an error message also provides the path to the php.ini file.Edit the memory_limit parameter in the php.ini file (usually in a section called Resource Limits). Make sure you use M to specify the number of megabytes (not MB).memory_limit = 256M ; Maximum amount of memory a script may consume (256MB)If there is no section already for this, place the above line at the end of the file.Restart Apache.