Problems with new install (no replies)

Brand new to Piwik. I just tried installing it several time on a shared server, each time I ran into the following errors:

After install, under the login block I see

"A fatal error occurred

Please contact the system administrator, or login to Piwik to learn more."

When I try to login I get the following error and I am not logged in.

"Zend_Session is currently marked as read-only."

After refreshing the page I am taken to my dashboard but many of the panels have the warning

"A fatal error occurred
The following error just broke Piwik (v2.5.0):
XCache: Cannot init
in Unknown line 0"

I have adjusted the .htaccess file with the following but the problem remains

php_flag xcache.cacher Off
php_flag xcache.size 0
php_flag xcache.stat Off

In piwik's error log I see

[29-Aug-2014 14:30:01 UTC] Error in Piwik (tracker): Invalid idSite: '0'

In my server error log I see

2014-08-29 10:30:16.935 [NOTICE] [IP.IP.IP.IP:60795-0#APVH_domain.com] [STDERR] Error in Piwik: Session must be started before any output has been sent to the browser; output started in /path/analytics/plugins/Installation/Installation.php/95


Any suggestion?

Thanks