NFC shield and Sparkfun USB shield

I have got the Seeedstudio NFC shield and the Sparkfun USB shield ( working on there own. However when I’m stacking both shields on an Arduino Duemilanove (ATMEGA328) they stop working. Is there a solution for this? Thank you so much!

I don’t know much about either board, but when working shields are incompatible, it may be that they are each trying to use the same data pins for different purposes. It may be possible to remap data pin usage, but that is tricky, and probably requires software changes.