The date on the IBM AIX installation of the sdeexe90/bin directory may list with a date of Dec 31 1969. This is a bug with AIX tar command. This does not affect the ArcSDE software.
The problem can be resolved by applying IBM patch PTF U496216 to get bos.rte.archive.188.8.131.52.
The same problem may be seen with the sdeexe90/tools directory of the AIX Software Development Kit.