You're just gonna have to work that out between whatever shields you have. Check out
the schematics, etc. Many shields seem to have marginal designs. You may have to cut
some traces, and patch software, to get shields to play nice together, or toss some shields
in the closet, and buy something else. XBee shields are notorious for this kind of problem
too.
EDIT: the other option is, you can try using the software SPI commands to connect to the
NRF2401 module, and use a different set of pins than 10..13,
http://arduino.cc/en/Reference/ShiftIn
http://arduino.cc/en/Reference/ShiftOut