سلام
سايت ما جوملا 1.5 است و الان بالا نمي آيد و بجاي صفحه اول اين خطا را مي دهد:

jtablesession::Store Failed
DB function failed with error number 145
Table './hamorg_2010/jos_session' is marked as crashed and should be repaired SQL=INSERT INTO `jos_session` ( `session_id`,`time`,`username`,`gid`,`guest`,`client_id` ) VALUES ( '57bc8179bbc1a62119f7106a345c91d4','1347255793','','0','1','0' )
Fatal error: Allowed memory size of 268435456 bytes exhausted (tried to allocate 71 bytes) in /home/hamorg/public_html/2010/libraries/joomla/error/exception.php on line 117

براي رفع اين مشكل چه بايد كرد؟
با تشكر