This is a flash I found on the subject:

Abstract: Installation of IBM Tivoli Storage Manager V5R2 requires AIX 5.1
ML1 or higher levels of AIX

Who is Effected:
IBM Tivoli Storage Manager Version 5, Release 2 customers using AIX 4 .

Problem:
Installation of IBM Tivoli Storage Manager V5R2 requires AIX 5.1 ML1 or
higher levels of AIX.

Based on IBM support for AIX 4.x Operating systems being withdrawn
December 2003 ITSM V5R2 is not supported on AIX 4.x Operating Systems.

GA Publications and README files do not identify the change in AIX and
ITSM Support. Future releases of ITSM Publications and README files will
no longer list AIX 4 as a supported platform.

Recommendation:

To install and use IBM Tivoli Storage Manager v5r2 for AIX, first upgrade
your Operating system to AIX 5.1 ML1 or later.

-Darrius Plantz
IBM/Tivoli