I'd suspect that the two machines do have different architectures, the one with the incorrect results being on 64 bits.
in reply to Same DBI version gives different output on different machines
That won't help too much - but maybe you can try further steps then to track the problem down, maybe to an library that isn't the right one for the given architecture.
Update: Sorry, I haven't noticed the uname -a in your original post, showing that the two machines are both x86-64. Still, it has to be something about the 64 bits libraries that differ on one machine.