Doh! I'm really NOT this stupid, but I just can't get it to work. For some reason, regardless of what control byte I send, the ADC reports results from any channel.

If I set a control byte to sample channel 0, the mCU reads the right result - then if I switch the analog input to channel 1-7, the same results are reported to the mCU.

All channels are terminated to GND through 10K resistors. A 10uF and a .1uF are within 1 CM of the ADC chip. Help...? :-)