IDOCs are sitting in status 64

Hi,

I have an issue with inbound IDOCs posting. We are receiving the IDOCs for sales orders. As soon as we receive the IDOCs, sales orders should be posted automatically. Because we set the procese code as 'Trigger Immediately'. But IDOCs are coming into SAP and sitting in 64 status. We are going to transaction BD87 and manually posting them.

We are not able to figure out the reason for IDOCs sitting in 64 status, even though all the required IDOC settings are in place.

Could anybody tell me the reasons for the above problem.

Thanks in Advance.