ORA-27300: OS system dependent operation:invalid_process failed with status: 0
ORA-27301: OS failure message: Error 0
ORA-27302: failure occurred at: skgpstime3
ORA-27144: attempt to kill process failed

See Note 458442.1 10.2.0.3 PMON CRASHES ON STARTUP ON AIX 5L 5.3 ML05 -- WORKS on ML06

sample：
Mon Jan 25 22:18:46 2010
Errors in file /oracle/oms/admin/JTOMS/udump/jtoms_ora_987230.trc:
ORA-27300: OS system dependent operation:invalid_process failed with status: 0
ORA-27301: OS failure message: Error 0
ORA-27302: failure occurred at: skgpstime3
ORA-27144: attempt to kill process failed