When the N.C. Legislature convenes next month, taxation again will be on the GOP agenda. Lawmakers already are hearing from voters and businesses about new sales taxes on services. Example: if a fixture that requires plumbing is installed by the business which sold it, that business has to charge tax on the labor used in installation. If the fixture is installed by an independent contract plumber, the labor is not taxed. Also, taxes on labor for automotive repairs is not popular with voters. But once the lid is opened on taxation issues, the results often end up like a Pandora’s box.