We've had nodes here about bugs in people's code, where things didn't work as expected, and the cause was the use of "A", "B", and "C" as the package names (I might actually try to locate one, soonish). The cause is B comes with perl, and is the root to a module suite, to compile/decompile perl scripts. When I say B::Deparse the lightbulb might just flash to on.

Just don't use "A", "B" etc. You could try "Alpha", "Beta" instead, or maybe even "Foo", "Bar".