SPUG: Modules screwing each other up.

[jlb]

The only time recently I ran into an issue with modules screwing one 
another up had to do with XML::Twig importing UNIVERSAL::isa, which is 
apparently a bad thing for reasons I am not entirely clear on.

Though, I would be interested in understanding the issue better if 
someone can explain.  Confusingly, the UNIVERSAL code examples import isa, 
then strongly recommend against doing so.

Jon