The skipping problem your talking about, does it sound more like the phatbox is playing & then stop. I've heard it a couple times but to me it sounded like the audio cables were loose and it caused a little static feed back?
Cure for Phatbox skipping!!
Just cam across this ingenius fix for the skipping problem when connecting a Phatbox to the MFD navs:
http://4130-products.com/step/Phatbox/
http://4130-products.com/step/Phatbox/
