[otrs] Duplicated Tickets

Hello everyone. I am working for first time with otrs. I implemented it for my company, and almost everything is great. Almost, because some times and until now aleatory, when i create a ticket otrs creates a duplication. Does anyone  knows why this is happening? Regards, Yrving ¡Todo sobre Amor y Sexo! La guía completa para tu vida en Mujer de Hoy. http://mx.mujer.yahoo.com/