FPBX 2.11 logs out when clicking menu item

Hi,

We are running centos 5.10, asterisk 1.8 and FPBX 2.11
This was upgraded from 2.9 to 2.10 and then 2.11 via the fpbx module updates page

Now when I login to freepbx, every time I click on a menu item it logs me straight out again

Looking at similar issues I thought it was either a permissions thing or php session
So i did an amportal chown
I also checked the permissions on /var/lib/php/sessions
nothing seems to work

I also tried setting the sessions directory to 777, yet no php session ever gets created in that folder, so Im not sure why that would be

could it be that Im being logged out because no php session is being created? if so why would that be if all my permissions seem correct?

Clear your cookies
Make sure you have clicked apply config
Make sure core and framework are up to date.

Already checked all of that!
I cannot apply config as i get the error “XHR response code: 200 XHR responseText: undefined jQuery status: parsererror”

re-installed FPBX 2.11 from tar now, but still no luck
however, the php sessions are now being created in /var/lib/php/session

unfortunately I still get logged out when I click on a menu item and I get “XHR response code: 200 XHR responseText: undefined jQuery status: parsererror” when I click on the commit button

There are no errors in the html error log and just the normal GET entries in the access log

Im running PHP 5.2.5 on this system (centos 5) could that be the reason??