SQL*Loader: puzzling with ORA-03106

Question

Hello All,
I got a process that loads 3 files into a 8.1.7.2.0. Database. It uses DIRECT Path to load it. If the database is freshly started it loads the first 2 files and fails with the third one with:
Error during upi fetch: [100]
ORA-03106: fatal two-task communication protocol error
SQL*Loader-704: Internal error: uldisconnect [-1]
ORA-00600: internal error code, arguments: [729], [64], [space leak], [], [], [], [], []
If it's not started freshly it can't even load a single file. But if I do the load without DIRECT it works.
In a forum I found a hint to the Parameter SESSION_CACHED_CURSORS. I then changed it from 100 to 0 and it worked.
But I don't see the reason for that behaviour!
Any hint is appreciated!
Imre

Answer 1

03135, 00000, "connection lost contact"
// *Cause:  1) Server unexpectedly terminated or was forced to terminate.
//          2) Server timed out the connection.
// *Action: 1) Check if the server session was terminated.
//          2) Check if the timeout parameters are set properly in sqlnet.ora.I would suspect networking issues external to sqlldr & Oracle