civicrm_participant table not grabs records

[tartalo]

I am in 4.5beta8 but with the version 4.4 had the same problem, so I decided to upgrade to 4.5
When I record an event (event register online) from Drupal (7.31), it seems not civicrm_participant record is inserted, and that makes civicrm_participant_payment insert attempting, into error by the unfulfilled relationship.
Any help where I can look?

thanks

backTrace

#0 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Error.php(191): CRM_Core_Error::backtrace()
#1 [internal function](): CRM_Core_Error::handle(Object(DB_Error))
#2 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/PEAR.php(931): call_user_func((Array:2), Object(DB_Error))
#3 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB.php(975): PEAR_Error->PEAR_Error("DB Error: constraint violation", -3, 16, (Array:2), "INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...")
#4 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/PEAR.php(564): DB_Error->DB_Error(-3, 16, (Array:2), "INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...")
#5 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/common.php(1905): PEAR->raiseError(NULL, -3, NULL, NULL, "INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...", "DB_Error", TRUE)
#6 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/mysql.php(899): DB_common->raiseError(-3, NULL, NULL, NULL, "1452 ** Cannot add or update a child row: a foreign key constraint fails (`gu...")
#7 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/mysql.php(328): DB_mysql->mysqlRaiseError()
#8 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/common.php(1216): DB_mysql->simpleQuery("INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...")
#9 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/DataObject.php(2442): DB_common->query("INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...")
#10 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/DB/DataObject.php(1060): DB_DataObject->_query("INSERT INTO civicrm_participant_payment (participant_id , contribution_id ) V...")
#11 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/DAO.php(455): DB_DataObject->insert()
#12 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Event/BAO/ParticipantPayment.php(63): CRM_Core_DAO->save()
#13 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Event/Form/Registration.php(790): CRM_Event_BAO_ParticipantPayment::create((Array:2), (Array:0))
#14 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Event/Form/Registration/Confirm.php(642): CRM_Event_Form_Registration->confirmPostProcess("943", Object(CRM_Contribute_BAO_Contribution), NULL)
#15 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Form.php(328): CRM_Event_Form_Registration_Confirm->postProcess()
#16 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/StateMachine.php(162): CRM_Core_Form->mainProcess()
#17 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/QuickForm/Action/Next.php(60): CRM_Core_StateMachine->perform(Object(CRM_Event_Form_Registration_Confirm), "next", "Next")
#18 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/HTML/QuickForm/Controller.php(203): CRM_Core_QuickForm_Action_Next->perform(Object(CRM_Event_Form_Registration_Confirm), "next")
#19 /home/gurutzeko/www/www/sites/all/modules/civicrm/packages/HTML/QuickForm/Page.php(103): HTML_QuickForm_Controller->handle(Object(CRM_Event_Form_Registration_Confirm), "next")
#20 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Controller.php(356): HTML_QuickForm_Page->handle("next")
#21 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Invoke.php(331): CRM_Core_Controller->run((Array:3), NULL)
#22 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Invoke.php(75): CRM_Core_Invoke::runItem((Array:15))
#23 /home/gurutzeko/www/www/sites/all/modules/civicrm/CRM/Core/Invoke.php(52): CRM_Core_Invoke::_invoke((Array:3))
#24 /home/gurutzeko/www/www/sites/all/modules/civicrm/drupal/civicrm.module(457): CRM_Core_Invoke::invoke((Array:3))
#25 [internal function](): civicrm_invoke("event", "register")
#26 /home/gurutzeko/www/www/includes/menu.inc(517): call_user_func_array("civicrm_invoke", (Array:2))
#27 /home/gurutzeko/www/www/index.php(21): menu_execute_active_handler()
#28 {main}

[adixon]

Your line #6 about the foreign key constraint looks to be the key piece of information - the row likely has foreign keys in both the contribution and participant table which it's trying to join together, and one of the values must be invalid (i.e. the participant id or the contribution id). Could be a corrupted table structure, I suppose, or perhaps the real error occurs earlier and only gets triggered at this point (i.e. check to make sure both the contribution records and participant records for the registration are correctly saved.)

[tartalo]

Thank you.
I just do not understand.
the civicrm_participant table has no relation with civicrm_participant_payment.
only civicrm_participant_payment references to civicrm_participant
I have no error that says tat in the try to insert into civicrm_participant_payment, not possible.
if I unchek the option of event payment all goes well.

sorry for my english

[tartalo]

if I delete the relationship referred to civicrm_participant table, no error. the record is created in civicm_participant_payment but NO civicrm_participant record is created.
This happens from online registration.
If I make the offline registration from CiviCRM, all goes well, the records are inserted in the 2 tables.
any help please?

[adixon]

Is it a paid event? If so, what payment processor r u using?