Unfortunately the Serial module of Net::Appliance::Session is proving very difficult to fix. I can't in all honesty say I'll be able to make it work :-(
I am working on a complete rewrite of Net::Appliance::Session and
because it will work in a different way, I hope to work around all this.
Sorry about this, and please revisit the module in the future if you
have time to try it again. I'm not sure there's much else like it
around, and the new version will (I hope) kick ass.