ORA-00600[[qmxiUnpPacked2]

Database Version: 9.2.0.7
OS: Windows


We you get below error message during "drop user" statement
ERROR at line 1:
ORA-01001: invalid cursor
ORA-00600: internal error code, arguments: [qmxiUnpPacked2], [121], [], [], [],
[], [], []

then please check metalink note: Note:339070.1

This is generally caused by an invalid upgrade from earlier release.