how to reve Extra special characters from source file

Hi all

I am doing an file to idoc scenario in which i am using SEEBURGER BIC adapter for converting flat file to xml.My input file contain HEADER ,ITEMHEAD AND FOOTER.When i am processing an error is coming extra charcterYP persent before header.While in input file its not visible,it might be some special controll character

my file is with utf-16 format( little endian) encoding.

Plz share if u have any idea about the sudden occurence of special character and how to overcome it.

Regards

Saurabh Sharma