Additional ISR calls (from SPI0?)

[xsrf]

Running the example code, I sometimes do get a lot of additional ISR calls while the first 64 bytes of data are sent via SPI1.

I'm not at all sure if I'm handling the Interrupt flags right... Could this cause some issues?
I guess these are ISRs for SPI0. I had to clear these, otherwise the ISR wouldn't be called again...

nbSPI/nbSPI.h

Lines 91 to 94 in d5b51d5

	if(SPIIR & (1 << SPII0)) {
	// SPI0 Interrupt
	SPI0S &= ~(0x1F); // Disable and clear all interrupts on SPI0
	}