Exchange 2003 Failing to service client requests. event ID 9074?

Hi guys

Hope someone can help me with this error that im getting in my event viewer. it seems to appear everytime the server downloads mails, the error reads “The Directory Service Referral interface failed to service a client request. RFRI is returning the error code:[0x3f0].” It seems some clients arnt gettin their mail sometimes. if someone has some angles to tackle this with please let me know.