Successfully using VAS 3.x version on AIX 5.2. After upgrading Operating System to AIX 5.3, you start getting erratic behavior and core dumps.
VAS client installation requires a specific package for AIX 5.3, which is different than the one that is used for AIX 5.1 and AIX 5.2.
Uninstall the existing VAS package and install the one for AIX 5.3. This will resolve the issue.