I have 2 servers, both with the same initial DataBase and the same Aplications and processes.

When loading with SqlLoader a text file (the same file in both), one server reject some records that the other don't. The server that reject those records presents an integrity constrains error for them (ORA-00001). But this fact is an error, because those records don't have duplicity. And this fact occurs alleatory in this server each day with some records, but only in the same unique table. The PK is the same in both machines.

In the "bad" server I inserted manually a record that SqlLoader rejected, and it was accepted. Then, SqlLoader in the "bad" machine have problems.

Release of "good" machine is 8.1.6
Release of "bad" machine is 8.1.5

The OS is NT Server 4 Service Pack 6, in both servers.