I assume that you use ODBC or OLEDB to connect to the Teradata database. Then the problem lies in the connection to the database, so check the connection string.
It could be many different things:
* Do you use the same UserID / Password to connect to the DB? (Authorization can cause this difference)
* Do you load from the same internal database?
* Do you use the same table in the SELECT?
* Do you use the same character encoding? (A where-clause in the SELECT could depend on the character encoding)