Mystery problems in complex systems

Yeah. Definitely a possibility.

We had a machine built (with CentOS 5) a little while back, handed over to us as working. We
discovered it didn't have a compiler installed (perils of letting non-developers specify the
machine). So 'yum install gcc' and Yum immediately segfaults. Tried manually updating the
kernel because someone suggested a recent AMD bugfix could be related. Still segfaults. Well,
that was bad news, so I tried replacing Yum RPMs manually, got nothing. Eventually we found
that RPM libraries were corrupted somehow, replaced those, and Yum was working, but soon after
installing GCC I ran 'less' and that segfaulted. While investigating this, the disk became
read only and the kernel reported serious ext3 corruption.

So we turned it off and handed it back over as faulty hardware, suspected RAM or disk failure.
But the hardware guys ran every diagnostic they could think of, found nothing and re-installed
CentOS. And now it seems fine (we have some fairly hard-core correctness tests still to run on
the finished system of software + hardware). So what happened there? Corrupted install media?
Cosmic rays? Some new type of malware? Just good old PEBCAK?

Normally I would want to understand, but in this case hunting for the answers seems likely to
be fruitless. If the Fedora people have some mystery symptoms it would be nice if they set
themselves (and told us) a deadline where they'll declare it just another unsolved mystery,
like a headless torso washed up on a beach with no identifying marks.