issue customer master data idoc

Hai gurus,

the scenario is that ours is a sender system and other is receiving system.

customer master data is sent form our system and other receives it.

what happened here is idoc is sent to the other system and data went to other system is incorrect

example : sender system Receiving system

customer master

First Name DAVID constant

Last Name DECOSA DECOSA

so when the idoc is sent the 'first name ' of the customer is getting "constant".

what could be the possible reasons for it?

It is urgent and could help in this case.

Thanks in Advance

sameer