Hi,
I use this:

DEFINE OSC 4
DEFINE ADC_BITS 8
DEFINE ADC_SAMPLEUS 50
' Set clock source (3=rc)
DEFINE ADC_CLOCK 3


......................

for counter2 = 0 to 7
SUM = 0
FOR COUNTER1 = 1 to 10

ADCIN counter2,A[counter2]

PAUSEUS 24 'Pause between ADCINs

SUM = SUM + A[counter2]

NEXT COUNTER1

A[counter2] = SUM/10


And is working very good.

Regard.