This error can occur on an AIX Apache Web Agent install when there is a bit level mismatch between the Web Agent and the Web Server.
Check the bit level of the IBM IHS webserver and the Web Agent installer that was used.
To check the IBM IHS webserver bit level, run:
# apachectl -V
Server version: IBM_HTTP_Server/188.8.131.52 Apache/2.0.47
Server built: Nov 19 2009 12:21:35
Build level: IHS60/webIHS0946.03
Server's Module Magic Number: 20020903:4
Server compiled with....
The Web Agent packages are easily labeled to identify which is the 64 bit version.
Using the appropriate installer will correct the error. In this example, the 32 bit Web Agent would need to be installed to match the 32 bit IBM HTTP Server(IHS).