Customized download data

I have a MBO (SUP2.1) derived from SAP BAPI, Customer.GetList and am trying to use SQL statement in synchronization tab by clicking 'Customized download data' to limit columns. Original and modified SQL looked like:

SELECT x.* FROM GetList x WHERE ( (x.CITY=:sp_city ) )

SELECT x.CUSTOMER, x.NAME, x.CITY FROM GetList x WHERE ( (x.CITY=:sp_city ) )

If I deploy project with modified SQL, it just fails saying 'Delpoy error' not giving any details.

Can anyone enlighten me?