[development] user cannot edit a node despite node_access_records

I have developed a node access module with drupal 6, and a user who should be able to view and edit a node only can see it. Any idea? Thanks -- *Ser freak no és imprescindible per ser informàtic, però ajuda. *La vida no ha de ser feliç, ha de ser plena. *Abans d'imprimir aquest missatge, pensa en el medi ambient.