Leslie Vail has details on the Payroll Tax Round 2 for GP2010 for year 2011. This is supposed to be the fix for the FICA issues introduced by new tax laws.
Dynamics Confessor Blogspot: Payroll Tax Round 2 for GP2010 for year 2011
Payroll & HRMicrosoft & the GP EcosystemGP 2010
Archived post from 2011. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.