I also have developed this problem in the last few days.
With debug on:
Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 261900 bytes) in /usr/local/www/grantarc-new/administrator/components/com_comprofiler/library/cb/cb.acl.php on line 498
So I increase the PHP memory_limit to 512M and I get this:
Fatal error: Allowed memory size of 536870912 bytes exhausted (tried to allocate 261900 bytes) in /usr/local/www/grantarc-new/administrator/components/com_comprofiler/library/cb/cb.acl.php on line 498
There must have been an update to Joomla3 or CB that is causing a memory leak. I increased the memory all the way up to 24G (I have 32G ram in the machine) and the pattern continues.
I have checked that I have plenty of free space on the drives.
OS: FBSD 8.2
Apache: 2.2.21
Joomla: Joomla! 3.0.3 Stable [ Ember ] 04-February-2013 14:00 GMT
I have not installed anything new.