This is a known problem with SQL*Net 2.3, NT 4 and Integrated Debugging. The following solutions exist:
  • Rename or remove the registry entry HKEY_LOCAL_MACHINE\SOFTWARE\ORACLE\OTRACE73. This is the solution that Oracle support recommends!
  • Start Oracle's Installer and remove the "Oracle Trace Collection Services 7.3.x.x.x"
  • Turn off Integrated Debugging in the IDE
  • Use an Oracle SQL*Net version other than 2.3