Error memcache

[poison26]

I have this error on my site. It's my problem ot yours?

I use joomla 1.5.23

[21-Sep-2011 02:45:55] PHP Warning:  Memcache::get() [<a href='memcache.get'>memcache.get</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 205
[21-Sep-2011 02:45:55] PHP Warning:  Memcache::delete() [<a href='memcache.delete'>memcache.delete</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 209
[21-Sep-2011 02:45:55] PHP Warning:  Memcache::delete() [<a href='memcache.delete'>memcache.delete</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 210
[21-Sep-2011 02:45:55] PHP Warning:  Memcache::get() [<a href='memcache.get'>memcache.get</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 126
[21-Sep-2011 02:45:55] PHP Warning:  session_start() [<a href='function.session-start'>function.session-start</a>]: Cannot send session cookie - headers already sent by (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 423
[21-Sep-2011 02:45:55] PHP Warning:  session_start() [<a href='function.session-start'>function.session-start</a>]: Cannot send session cache limiter - headers already sent (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 423
[21-Sep-2011 02:45:55] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 426
[21-Sep-2011 02:46:07] PHP Warning:  Memcache::get() [<a href='memcache.get'>memcache.get</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 205
[21-Sep-2011 02:46:07] PHP Warning:  Memcache::delete() [<a href='memcache.delete'>memcache.delete</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 209
[21-Sep-2011 02:46:07] PHP Warning:  Memcache::delete() [<a href='memcache.delete'>memcache.delete</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 210
[21-Sep-2011 02:46:07] PHP Warning:  Memcache::get() [<a href='memcache.get'>memcache.get</a>]: No servers added to memcache connection in /home/poison/public_html/libraries/joomla/session/storage/memcache.php on line 126
[21-Sep-2011 02:46:07] PHP Warning:  session_start() [<a href='function.session-start'>function.session-start</a>]: Cannot send session cookie - headers already sent by (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 423
[21-Sep-2011 02:46:07] PHP Warning:  session_start() [<a href='function.session-start'>function.session-start</a>]: Cannot send session cache limiter - headers already sent (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 423
[21-Sep-2011 02:46:07] PHP Warning:  Cannot modify header information - headers already sent by (output started at /home/poison/public_html/libraries/joomla/session/storage/memcache.php:205) in /home/poison/public_html/libraries/joomla/session/session.php on line 426