in reply to Extremely weird module issue...

Here's where it gets weird. If I remove the pod, the test script works fine. If I put it back and remove the doCmd sub, it works just fine. And if I move the module into the same directory as the test script (renaming and amending use statement), it works fine.
hmm... source filter (Switch) screwing things?
BUGS
There are undoubtedly serious bugs lurking somewhere in code this funky :-) Bug reports and other feedback are most welcome.
- just a guess, as you say removing the doCmd sub (the one that uses switch) makes the thingy work.

--shmem

_($_=" "x(1<<5)."?\n".q·/)Oo.  G°\        /
                              /\_¯/(q    /
----------------------------  \__(m.====·.(_("always off the crowd"))."·
");sub _{s./.($e="'Itrs `mnsgdq Gdbj O`qkdq")=~y/"-y/#-z/;$e.e && print}