Different byte-code in same major version (2.6.x)?

[Paul Rubin]

Hartmut Goebel <h.goebel at crazy-compilers.com> writes:
> I'm facing a curious problem: 2.6, 2.6.1 and 2.6.4 are generating
> different byte-code for the same source. I can not find the reason for.

Why should they generate the same bytecode?  All that you should expect
is that the same bytecode should be runnable on all three interpreters.
It is ok if a newer version of the compiler does additional
optimizations or that sort of thing, resulting in different bytecode.
It's just like with any compiler.