non-recoverable error, DB Error: no such field

DB Error: no such field

SELECT contact_a.id as contact_id, civicrm_value_domain_11.id as civicrm_value_domain_11_id, civicrm_value_domain_11.domain_22 as custom_22 FROM civicrm_contact contact_a LEFT JOIN civicrm_contribution ON civicrm_contribution.contact_id = contact_a.id
LEFT JOIN civicrm_value_domain_11 ON civicrm_value_domain_11.entity_id = civicrm_contribution.id WHERE ( contact_a.id = Array ) LIMIT 0, 25 [nativecode=1054 ** Unknown column 'Array' in 'where clause']

This happens when Anonymous tries to check out. Logged in users work fine.

Any ideas?