How do we set up the JDE system when we have 27 biweekly pay periods this year?

We are wondering if we set up 27 pay cycles in the Master Pay Cycle or if we use pay cycle 26 twice at the end of the year.  When we were testing 2014 (next year), we found that when we have 27 pay cycles set up, the federal withholding tax is different than when we only have 26 pay cycles.  It seems that if the gross pay is the same (yes, we will end up paying employees more in the year we have 27 pay periods), the taxes should be the same regardless of whether we have 26 or 27 pay periods.

I am also wondering if we have to adjust the UDE 06/PF or 07/PF.