automatic update problem

I am trying to autoupdate to 3.3.1 and I am getting this error message:

Fatal error: Out of memory (allocated 28311552) (tried to allocate 4247825 bytes) in /homepages/14/d235474385/htdocs/screnews/wp-includes/class-http.php on line 1426

I have tried restarting my computer to clear my cache. Please let me know if you have any ideas on how to get the update to work. I’d rather not have to do it manually.