Could this problem be related to the one being discussed here: http://e2e.ti.com/support/low_power_rf/f/538/p/227515/802731.aspx#802731
I am seeing missing bytes on the UART port when using ISR and some of the TI Employees are hinting at the possibility of conflicts when BLE communication and UART ISRs are happening at the same time.
Are you using DMA or ISR to receive your SPI?
