> unfortunatly I haven't a solution for the bytecode stuff. I only use
> ocaml with native compiled code. This works very well.
>   
Native code would also be sufficient (to save me from translating lot of 
code to C).

The problem is that the assembler available on AIX doesn't unserstand 
power-aix.S:

as  -o power-aix.o power-aix.S
Assembler:
power-aix.S: line 103: 1252-023 The symbol .caml_garbage_collection is 
not defined.
power-aix.S: line 103: 1252-087 The target of the branch instruction
        must be a relocatable or external expression.
power-aix.S: line 457: 1252-023 The symbol caml_young_limit is not defined.
power-aix.S: line 457: 1252-040 The specified expression is not valid.
        Make sure that all symbols are defined.
        Check the rules on symbols used in an arithmetic expression
        concerning relocation.
...... (many similar messages)

How have you obtained running ocamlopt?

Dawid