I've set up a new server for my magentocommerce.
Unfortunatly when I moved the domain to the new location (tests have been done using another domain) a weird issue started happening: when the login page displays on the frontend, or the backend and I (and customers, of course) do submit the right credentials the page refresh, the cookie gets set but the form is displayed again. It's such a cache being served instead of the right content (catalog).
The only solution actually is delete the cache on the browser and retry.
I've used varnish http accelerator for two days, but since I've had too much issues dealing with it I uninstalled it and cleaned things up (now there's only the apache instance to serve user requests).
I also installed APC caching and Fooman Speedster.
What can it be to cause this issue?
Can you please help me to get in the right direction to fix this issue? On the old server it was not happening, but since that time there have been some modification to the store (nothing to do with authentication anyway).
The apache error log does not report anything, the only thing in there is PHP: syntax error, unexpected BOOL_TRUE in /etc/php5/apache2/conf.d/apc.ini on line 4
which has to do with the line apc.enabled = 1
.