LPX-00200:could not convert from encoding UTF-16 to ISO-8859-1

 I have a process which reads information from a file being sent to our organization.I use DBMS_LOB.LoadClocbFromFile to load the data into a table with a clob column.

Once the data is in the clob field I try to set another column of xmltype in the same table 

with a 

update uw_file_import_log set xml_data=xmltype(src_clob,nls_charset_id('AL16UTF16')

  where query_id=p_query_id;

When I do this in  development 11g database which has NLS_CHARACTERSET = WE8MSWIN1252 is works fine.

When I do it in a 10 g environment which has NLS_CHARACTERSET = WE8ISO8859P1 is gives an error.