Wiring the LEDs on the Ethernet module causes problems, so forget that. I also had a strange issue where I couldn't get it to work correctly unless I hooked up a probe on the chip select line. I've emulated this with a 10MOhm resistor and a 100pF capacitor. This is a short-term solution which may end up sticking if we don't have time to fix it.
Moved the weight sensors from ADC0 to ADC1. Channels 1 and 2 on ADC0 seem to be bad. The sensors have been tested and are working correctly. A function has been written to determine whether or not the alarm should be active (from the weight sensors' perspective) given lower and upper thresholds, which are determined by calibration.