CiviCRM ACL causes MySQL to crash

SELECT SQL_CALC_FOUND_ROWS contact_civireport.sort_name AS civicrm_contact_contact_source,
        GROUP_CONCAT(DISTINCT civicrm_contact_assignee.sort_name  ORDER BY activity_assignment_civireport.assignee_contact_id SEPARATOR '^A') AS civicrm_contact_contact_a
ssignee,
        GROUP_CONCAT(DISTINCT civicrm_contact_target.sort_name  ORDER BY activity_target_civireport.target_contact_id SEPARATOR '^A') AS civicrm_contact_contact_target,
        activity_civireport.id AS civicrm_activity_id, activity_civireport.source_record_id AS civicrm_activity_source_record_id,
        activity_civireport.activity_type_id AS civicrm_activity_activity_type_id, activity_civireport.subject AS civicrm_activity_activity_subject,
        activity_civireport.source_contact_id AS civicrm_activity_source_contact_id, activity_civireport.activity_date_time AS civicrm_activity_activity_date_time,
        activity_civireport.status_id AS civicrm_activity_status_id,
        GROUP_CONCAT(DISTINCT activity_assignment_civireport.assignee_contact_id  ORDER BY activity_assignment_civireport.assignee_contact_id SEPARATOR '^A') AS civicrm_activity_assignment_assignee_contact_id,
        GROUP_CONCAT(DISTINCT activity_target_civireport.target_contact_id  ORDER BY activity_target_civireport.target_contact_id SEPARATOR '^A') AS civicrm_activity_target_target_contact_id,
        case_activity_civireport.case_id AS civicrm_case_activity_case_id
FROM civicrm_activity activity_civireport

LEFT JOIN civicrm_activity_target  activity_target_civireport
    ON activity_civireport.id = activity_target_civireport.activity_id
LEFT JOIN civicrm_activity_assignment activity_assignment_civireport
    ON activity_civireport.id = activity_assignment_civireport.activity_id
LEFT JOIN civicrm_contact contact_civireport
    ON activity_civireport.source_contact_id = contact_civireport.id
LEFT JOIN civicrm_contact civicrm_contact_target
    ON activity_target_civireport.target_contact_id = civicrm_contact_target.id
LEFT JOIN civicrm_contact civicrm_contact_assignee
    ON activity_assignment_civireport.assignee_contact_id = civicrm_contact_assignee.id

INNER JOIN civicrm_acl_contact_cache aclContactCache_0 ON
  ( contact_civireport.id = aclContactCache_0.contact_id OR contact_civireport.id IS NULL )
    AND aclContactCache_0.user_id = 1332


/* xxxxxxxxxxxxxxxxxxxxxx If the following 2 INNER JOINS are commented, the query xxxxxxxxxxxxx
   xxxxxxxxxxxxxxxxxxxxxx does not crash the MySQL server. If either are left in  xxxxxxxxxxxxx
   xxxxxxxxxxxxxxxxxxxxxx a crash will occur.                                     xxxxxxxxxxxxx
*/
  INNER JOIN civicrm_acl_contact_cache aclContactCache_1 ON ( civicrm_contact_target.id = aclContactCache_1.contact_id OR civicrm_contact_target.id IS NULL )
    AND aclContactCache_1.user_id = 1332
INNER JOIN civicrm_acl_contact_cache aclContactCache_2 ON ( civicrm_contact_assignee.id = aclContactCache_2.contact_id OR civicrm_contact_assignee.id IS NULL )
    AND aclContactCache_2.user_id = 1332

/* xxxxxxxxxxxxxxxxxxxxxx */

LEFT JOIN civicrm_option_value
    ON ( activity_civireport.activity_type_id = civicrm_option_value.VALUE )
LEFT JOIN civicrm_option_group
    ON civicrm_option_group.id = civicrm_option_value.option_group_id
LEFT JOIN civicrm_case_activity case_activity_civireport
    ON case_activity_civireport.activity_id = activity_civireport.id
LEFT JOIN civicrm_case
    ON case_activity_civireport.case_id = civicrm_case.id
LEFT JOIN civicrm_case_contact
    ON civicrm_case_contact.case_id = civicrm_case.id
WHERE civicrm_option_group.name = 'activity_type' AND
                activity_civireport.is_test = 0 AND
                activity_civireport.is_deleted = 0 AND
                activity_civireport.is_current_revision = 1 AND ( contact_civireport.id = 1332 OR civicrm_contact_assignee.id = 1332 OR civicrm_contact_target.id = 1332 ) AND ( activity_date_time >= 20121001000000 ) AND ( activity_date_time <= 20121031235959 ) AND ( activity_civireport.activity_type_id IN (28, 29) ) GROUP BY activity_civireport.id  ORDER BY activity_civireport.source_contact_id ASC  LIMIT 0, 50