ATmega328P with NRF24L01+ and MySensors 2.0.0 sketch on it,
NRF connected to hardware SPI, CE on D5 instead of D9 (Arduino numbering) and CS on D6 instead of D10.
Everything is set correctly in the sketch, but still D10 will be initialized and put high, although not used.
The right CS pin will be used later, but this initialization of D10 is just wrong.
If I enable SoftSPI and set the D11-D13 as the ports to be used (so, using same ports but bit banging instead of HW), everything works correctly.
Had a quick check in the sources, but could not find where D10 is initialized.
This effect vanishes, if I change the default setting in the MyConfig.h
Tested with Arduino 1.6.9 and 1.7.10.